BCM Community

I am trying to bench test my Webasto. I have the circuit diagrams but there is one that is an early canadian version and the other is present version. I have run the wires to what the early version shows but as soon as I hook up the negative to my battery it blows the inline fuse. Anyone that has a good knowledge please give me a call. 918 408 8917.

Is that you Nick?


Thanks,
Bryan

Hi Bryan,

Second jack from the left on the module has a Black, Red, and Brown wire. Tye the red and black to positive, and the brown to negitive.

This will power up your unit and start a purge cycle first, then ignition, then fuel.

Do Not fire up the unit with no coolant in the heat exchanger!! You will melt the fuseable link at the top of the exchanger..

Swing open the burner, pull out the round venturi out of the exchanger, secure the venturi to the burner with clamps so that

the venturi is not inside the heat exchanger. Then you can bench test the burner. Oh, hook up the fuel line too... :o

You should have a circular flame pertrudding from the venturi about 6"..

Good Luck
Nick-

Nick,

I have my circulating pump hooked up with feed and return lines going into a seven gallon container of water. Do I need to prime the exchanger first by jumping the pump to fill it first? I have the brown to negative. The black is on the unit side of the toggle switch with the red going to positive and a fusible link between then a lead to the opposite side of the switch. This should do the same thing when I flip the switch right?

Thanks,
Bryan 

Hi Bryan,

Yes, it will do the same thing.

Since you have coolant hooked up you can also test your limit switches so leave the burner in the exchanger and bleed and air from the coolant system.

Use a thomometer that will read up to 220+ degrees and submerge it into your bucket. Your unit should cycle off at about 180 deg's then

cycle back on at about 140 deg's. This is done with the two limit switches on either side of the fuseable link at the top of the exchanger.

Does the unit still blow a fuse? or did you correct the connections?

I tried it the way you mentioned as well. The control board just clicks. Any way to test the control board? I did try to prime the water circulating pump. I think the impellor may be bad as it pushes very little water. I am just using garden size water hose.

Thanks,
Bryan

Ok,

Clicks in the module are good signs.... This means it's working.

You'll have to start testing... First get a continunity meter and test the fuseable link at the top of the exchanger. It screws into the

center between the two limit switches. It will have two white wires connected to it. If it's open, it's bad.. Same with both limits..

if any are open, they are bad. Next, test the blower motor in the burner. [this is the most common problem with Webastos] The

blower will either be stuck, or the motor will burn out from being stuck...  If blower doesn't turn with power, remove the module,

ignition coil, and remove the black plastic cover on the burner to expose the blower wheel/motor. Gently free up the motor by moving

it back and fourth without damaging the wheel or the gear that drives the fuel pump. If it frees up, your in good shape.

Good Luck
Nick-

Nick,

They all zero out on my ohm meter. So they are all closed. The motor turns freely. I just stuck a long screwdriver into the head and could turn the blades easy.

Any other ideas?

Thanks,
Bryan

Ok,

Next see if your system had any external safty's. Does your second jack from the left [module] have any more jacks connected to it?

Like the two green wires? All should be open or not connected Also check the cad eye next to the burner nozzle. It should read

< (less than) 1600 Ohms when burning and over 20,000 when dark. If all tests ok, then we can point twards the control module.

Nick-

It did have B3 still plugged in but it was only for control light. I took it out. Only pins in place are B1 on/off switch, B2 Batt Neg. & B4 Batt Pos.

I am not sure what to make contact with on the photo eye. there are two wires on one spade and one on the other. I tried just touching the two spades but it just showed open. Unless I did it wrong.

I did contact the igniter tips and they showed 8.48 if that helps  :-\

Thanks,
Bryan

I am about 98.5% I found the problem. I decided to take the protection cap off and check the motor connections since everything else seemed to check out ok. I even jumped the coils and had spark at the ignition electrodes. Once I pulled the cover and looked at the end of motor shaft and there it was. One of the field magnets apparently had come off during most likely its last run and was kicked sideways and worn down nicely on the corner (see photo below).

I did clip it back into place and hoped for the best but the controle module just clicked again as I thought it would.

So now what am I going to have to replace? Can I get a replacement field magnet? Probably not I am guessing  :(
So much for a good working take out  >:(

Am I stuck buying a new motor. It looks quite different from the newer units.

Thanks again Nick,

Bryan

That looks like the brush for the motor to me.  You could try taking the other side out and shaping the worn brush in the picture to match the curvature of the intact one.  Once the brushes wear in, they should have a uniform "C" shape to them where they contact the curvature of the armature on the motor. 

If you apply 12 or 24 volts (depending on the system) the motor should spin.

Here is a selection of manuals:

http://www.techwebasto.com/thermosystems_rv.htm#DBW_Series (http://www.techwebasto.com/thermosystems_rv.htm#DBW_Series)

Unfortunately I don't see brushes, only a motor in the parts list.   Is there a manufacturer/model on the motor itself?

Steve,

It is one of the brushes. It was about 12:30 in the morning when I found this so my brain was a little foggy  ::) The motor is a Bosch. It does have what appears to be a part number. I wondered if I could take the brush off and put it on my grinder wheel but was not sure if  I could get it close enough to work. I guess I can not hurt it anymore than it already is  :o

I have the service and parts manuals and the only option I saw as well was the complete motor. If it is not to expensive that may be the way to go since it is an older unit. On the other hand it does not appear to have been used very much.

Thanks,
Bryan

Hi Bryan,

Try what Steve suggested... I have done this in the past with other motors but not the bosch.

It couldn't hurt since the Bosch motor is in the $300 range..

Good Luck
Nick-

Ive also shaped odd brushes with a grinding wheel to fit various motors over the years and been quite successful at it. The trick is soldering together the two copper stranded wires.
and I got my Webasto installed and working....I bought this one from Nick on eBay recently.....makes lots and lots of hot antifreeze...seems to work well.

Best of luck..

Mark

Quote from: Stormcloud on November 28, 2009, 03:32:37 PM
Ive also shaped odd brushes with a grinding wheel to fit various motors over the years and been quite successful at it. The trick is soldering together the two copper stranded wires.
and I got my Webasto installed and working....I bought this one from Nick on eBay recently.....makes lots and lots of hot antifreeze...seems to work well.

Best of luck..

Mark

Thanks Mark!
I'm glad your happy!
Nick-

I will get my Dremel out and see if I can get it shaped correctly. And hope it works  :-\

Thanks for the additional help guys  ;D
I will update you tomorrow.

Bryan

I guess it's back to the drawing board  >:( I did grind down the brush, hooked everything up and still just a click from the control unit  ::). I then pulled the cover again and hooked juice right to the contacts on the motor. It took off like it should  ;D. Downside is I do not know how long that brush will last since I had to grind it down a bit to get it to the correct shape again. Maybe I can get a brush somewhere?

I did a volt test across pin C2 & C5 as stated in the troubleshooting section of the service manual and no voltage. So I am assuming the control unit is bad. I would guess that the switch that is fed by C2 & C5 is bad.

Bryan

Hi Bryan,

Is your unit 12v or 24v?

Nick-

Nick,

It is 12v. Have you ever taken a control unit apart? Or is it possible without destroying it?

Thanks

Bryan

Hi Bryan,

It sounds to me that you may have faulty connections somewhere since you stated the module makes clicks

telling me that it works... but, I could be wrong since I'm not there testing the unit myself..

I'm sorry to tell you that I have no used 12v modules to sell you and I can't sell you new any cheaper then anyone else.

New 12v modules are $525 and you can buy directly from sure marine below.
http://www.suremarineservice.com/287-962.aspx (http://www.suremarineservice.com/287-962.aspx)

Please check all your wireing and connections before you purchace new.

Good Luck
Nick-

Nick,

Does it make any sense that I would not have voltage between C2 & C5 on the control unit when I have it hooked to my battery? I am going by what the service manual said in how to test the control unit. Is that the same way you would test it, by jumping C2 & C5 while under 12v power?

Thanks,
Bryan

I looked at the manual and the circuit diagrams and it looks like the blower motor  (C2, C5) and the coolant pump (A1, A2) should have power when B4 is connected to +12V, B2 is connected to ground (-) and the on/off switch is on - +12V on B1 for about 2 minutes if the rest of the circuitry does not detect a flame.  Did you connect +12V to B1 as well?  If you do and there still is no power to the blower motor, I'd give it a shot and try opening it up.  I'd bet that the brush issue caused a short and that's what was blowing your fuse initially.  I've never opened one, but I'd guess there is a relay inside that closes to power the motor - either the contacts on the relay are burned or there is an internal fuse as well.   Worth a shot if a new one is over $500.....

Thanks Steve!

You are right on the money!!  Bryan, go ahead and open it up. There are tabs along the base and the aluminum cover will slide off.

There isn't a fuse inside but, you may find burnt contacts on the motor relay. You might get lucky and clean them with an emery board.

Let us know
Nick-

Did you connect +12V to B1 as well? Yes B1 & B4 are connected to + and B2 is to -. I am pretty sure that the brush was initially causing the fuse to blow.

I can hook 12v direct to the motor and it will turn fine. Unless there is an internal fuse or relay inside the control unit that is the only thing I can think of. I am not sure if the control unit comes apart without destroying it. I do not see anything around the motor. I am going to start testing each wire individully I guess  ::)

I do not have power to the coolant circulating pump lead either, I know that motor works as well as I have hooked it direct to 12v and it operated properly.

And just saw your post a I was typing Nick. Are you talking about inside the motor or the control unit?


Thanks guys,
Bryan

Control unit Bryan.

Good Luck
Nick-

Thought that was what you meant.

I took the cover off and found that one of the two points on Relay #1 was completely off and rolling around the inside  :( and the board had a couple of hot spots on the printed part of the board.
I do not know if I can repair this or not. I will check with a couple electronic places tomorrow to see what I can come up with.

Here are a cuople photos.

Thanks again for the help guys.

Bryan

Here is the back of the board. The circled areas have been a little toasty it appears.

My new quest is to try and find a new or new to me used relay. Does anyone have a control unit for 12v that has tested bad. Maybe I can pull the double pole relay from it.

In particular it is a double pole relay (in mine this is the only one) and is marked as relay #1.
The rest of the board appears ok. I took it to an electronics guy and we removed the relay. It is not a common relay is why I can not just pick one up. I have a couple other places I am going to check today locally for a relay.

The guy at the electronics shop said it looked to have a bad solder joint from the relay to the board. We think that could have assisted in the problem possibly. The other is that when the brush came off the motor it caused an arc back to the relay and caused the point to pop off  :-\

Thanks again for the help,
Bryan

Almost there!!!  The board looks OK, in the worst case you can solder in a jumper over the PCB traces, but it doesn't look that bad.  Are there any numbers on the bad relay (or the good ones)?  Maybe a manufacturer like Tyco or Omron?  There are several suppliers around that I can point you to, then it should be as simple as unsoldering the old and in with the new..

Steve,

Unfortunately there are no markings on the relay at all. On the board all it really shows is Relay 1, 2, 3 ,4 & 5. The PCB trace appears to be ok.

I have already removed the relay. Just trying to match it up is the fun part. We guessed it to be a 5-10 amp?

Next to one of the relays printed to the board is B429. But that one is a single pole.

Thanks,
Bryan

Hi, is there any chance to solder some wires, and mount a remote relay of some type?

Just trying to present some options

Dick Egler

Dick,

That is an option that I am going to try to avoid until I can eliminate finding one to solder inside the unit.

On another note I was talking to an owner of a passenger bus company and he stated that insurance companies made them pull all Webasto units from their coaches due to fires.

Anyone heard this. My thought would be from not keeping it cleaned and it sooted up. Any thoughts?



Thanks,
Bryan

There have been concerns about those fuel fired heaters in coaches, but primarily on coaches that are for hire, or carry passengers as a public transportation.

Remember the VW beetle that had a gas fired heater. A friend of mine, German and proud of it, bragged on his instant heat by flicking a switch, and you hear this roaring of the flame under the front 'hood'. It did give instant heat, but it was also a flame, and that, in the event of an accident, could create a volitile situation that might be of some concern.

Where you mount the unit, and where the fuel shuts off might be something to consider when thinking about the location of the unit. Piping is cheap, if you have to run another 50 feet, versus placing the unit where it could be broken away from the coach in the event of an incident.

Everything we do requires thought.

Quote from: bryanhes on November 30, 2009, 11:00:30 AM
Dick,

That is an option that I am going to try to avoid until I can eliminate finding one to solder inside the unit.

On another note I was talking to an owner of a passenger bus company and he stated that insurance companies made them pull all Webasto units from their coaches due to fires.

Anyone heard this. My thought would be from not keeping it cleaned and it sooted up. Any thoughts?



Thanks,
Bryan

Hi Bryan,

I belive that most of those fires were from operators that never cleaned any greese build-up from their coaches..
Alot of webasto's are mounted in the engine compartment where greese tends to accumulate and become flamable.
If an exhaust pipe from a webasto should brake off or rott through, a fire hazzard could be possible.. as the heat from
the exhaust is well within the range to start a fire.

Nick-

Nick,

To me it seemed more of an operators failure to maintain :o I know lots of things that can cause a fire if not maintained. Like your home furnace. Let it get dirty enough and there goes your house! Just a little preventative maintenance goes a long way.

Do you have any bad 12v control units lying around?

Thanks,
Bryan

Can you post a couple of pictures of the relay, and one of the bottom with the pin configuration?  I'm pretty sure I have some of the single pole ones at home, (Boston, and I'm in San Diego), but they are probably made by the same people that make the double pole one.  I'm trying to remember the manufacturer and where I got them....  Are there any identifying marks on the single pole ones?

Steve,

If you go back to page 2 of this post there are a couple of pictures. The one circled is the relay that is bad. It is an 8 pin, double pole single throw.

There is nothing on the relays only B429 printed on the PCB next to one of the single pole relays.

If you need a better picture of the pin locations I will post one when I get home from work.

Thanks,
Bryan

Quote from: bryanhes on November 30, 2009, 01:03:47 PM
Nick,

Do you have any bad 12v control units lying around?

Thanks,
Bryan

Sorry man... I have nothing in 12v right now. I do have a couple bad 24v modules. I wonder??....
I doubt it!
Nick-

Bryan the relay is probably a "Bosch" or a "Cibie"  (or something like that! ;D)
Webasto is/was a German product originally.
Those 2 and one other name I can't recall (or find any of laying around) are the "common" relays of choice in most German products I have dealt with.
And I am a Setra fan, so I do deal with plenty of "German products"


Also FWIW our insurance company has never once mentioned removing the Wabasto units from our buses!

Also FWIW Setra now puts the Webasto in the center of the bus in the rear luggage bay on the driver side in what they call an "energy system!" (shoot if ya gonna burn the bus, might as well start it in the middle where is can spread both ways! ;D)
;D  BK  ;D

The only problem I am having is trying to figure out the brand as there are no markings. Here are pictures of the relay itself.


I talked to Kraft Tours and they run them in their busses as well. I am not worried about it in my bus as I am very particular on maintenance.

Thanks,
Bryan

Here are a few more pictures of the relay and PCB showing pin locations. I guess I have to post several to get all the pics on here.

Bryan

And the last two to show the size. The relay is about 1" x 3/4".

If all else fails I have located an external relay I believe I can use for about $16.00

Thanks again,
Bryan

I've done a ton of searching, and I'm going to admit I'm stumped on this one, the relay appears to be a double pole single throw relay from the picture.  The pin-out on the board does not match anything I can find.  So, a couple more questions - Is there a manufacturer/model number on the board or the case (maybe Hella?)  Are there markings on the other relays - It doesn't look like it from the picture.

Here's a link to a guy that has a bunch of oddball relays, you could try giving him a call:

http://www.kenselectronics.com/lists/relays.htm (http://www.kenselectronics.com/lists/relays.htm)

There seems to be some Webasto stuff on Ebay in Germany and England for subtantially less money than the US

If you are not in a huge hurry I'll look at the relays I have at home when I get there at Christmas, maybe I can get a supplier at that point...

Hi Bryan,

Here is a thought until you find either another relay or a control box.. I'm no electronic curcuit board junkie but,

why not just jump it out for now.. That relay brings on the blower so, maybe just control the unit with your t-stat or switch.?

Anybody else know if this will work?

Nick-

Steve,
Yes it is a double pole single throw. The control unit does have Hella on the aluminum case. No markings on other relays either. I guess that is why Webasto gets $500.00 for them, they are top secret  ;D ;D Crap!!

Nick,

I can solder leads and run them to the outside of the box to an external relay. I think that would work. I am not in a huge rush but would like to get it bench tested at least and start planning my install a little more.

Thanks,
Bryan

Nick - I don't think using the thermostat to control the blower motor would work.  I think that it could turn the motor off too soon.  If you look in this doc http://www.techwebasto.com/heater_main/LIT699745A.pdf (http://www.techwebasto.com/heater_main/LIT699745A.pdf) on page 19, it looks like the blower motor runs for a while after the fuel is shut off, probably to cool the combustion chamber and purge any unburned fuel vapors.  I think you could have a case where the Webasto is still firing to heat the water and the thermostat would shut it down. The Webasto cycle isn't really controlled by the thermostat in the coach, it fires on and off to keep the circulating water at a certain temp until the thermostat in the coach says it's warm enough, then the webasto goes through a shutdown cycle, which keeps the blower running for a while. 

Maybe the relays are made by Hella, I'll do some scouting around...

Steve,

You are correct. The unit does go thru a cool down cycle after it is shut off. I have had a little luck talking to a tech at Webasto. He is also going to check his personal parts for something that could help. He apparently does a little bit outside of work and was in the field for some time working on them.

Thanks,
Bryan

Hi Bryan and Steve,

Maybe the Webasto tech guy will give you a better price on a new module..

Funny, The Webasto people sent a regional supervisor to my shop today to interview me for being an authorized Dealer..

I will know in 2 weeks!   If so, I will be able to reduce that high price for the module.....

Nick-

Nick,

That would be a good if you could get set up as a dealer. The tech can't do anything on new parts  :( but maybe has something in the good used.
I may have found a used 12v unit that quit working and the guy bought a new one. If he did not chuck it it might have a good relay  :o

As I was typing this I talked with a guy I know at United Diesel. He quoted me a new one for a really good price. I will probably get it if I cant fix this one.

I will keep hunting for a little while.

Bryan

YOU might try calling Dave haynes at vehicle systems (Aquahot, Hydrohot). They use the Webasto head in their units. Might have a dead control box.

I'll give them a try Craig.

Thanks

Unfortunately, they let Dave and many others go several months ago.  Not sure who is left there.

That is a terrible loss for many of us.  

The story I got was that after the owner was murdered in January , there was no funds left to keep the staff.  He had been keeping the company going out of his own pocket.  From what I have heard, he was a great guy.

I just did a search and was very surprised to hear that Hap's daughter has been charged with the murder:  http://www.denverpost.com/news/ci_11805248 (http://www.denverpost.com/news/ci_11805248)

I am not saying that they are tanking, just that they had to cut way back.


Jim

Jim,

That's terrible news. I had not heard that the owner had been murdered.

I had never met him. I did meet Dave once. He gave me a tour of the facility several years ago and did help me with
understanding my AquaHot B model. 

craig

Sorry that this thread has taken a bit of a turn, but I wanted to make one more statement about Dave Haynes.  He was/is a one of a kind.  He had some pretty significant health problems and you would never know it.  He was ALWAYS willing to go above and beyond for any customer - even us one-off customers. 

I am pretty sure I have his private number and have wanted to talk to him, but could never find the spare time.

Jim

To turn it a little more I heard through a good source that Harry Mitchel of Parliment Coach is buying Aqua Hot ah BlueBird and now Aqua Hot wonder what old Harry is up too. 



good luck

Bryan, I found a place that may have the parts you need talking to him today he said he has some older parts for the units 

Bus Service Inc
Sharon Springs Ks
1-888-287-3499

Thanks Clifford. I sent them an email and will try to call tomorrow. I had seen that they were a Webasto dealer a while back but it did not cross my mind.

Bryan

Good News- John at Bus Services has the relay I need and is shipping it out today for $10.00 + shipping  ;D
Hopefully that will get me back in business to bench test!

Thanks for all the help guys! I sure do appreciate it. I am almost a certified Webasto tech now  ;) Almost!

I will update you when I get the new relay soldered in.

Bryan

Just thought I would let you guys know that have not dealt with John at Bus Services. He is a heck of a nice guy. He was going to send me the relay for $10. Well he could not find his box of relays so is sending me a complete used control unit for the same $10. He did say the box had some electrolysis on it but it may still be a good unit. If not at least the relay would hopefully be good.

I might get lucky and it works fine, I hope  ;D

Bryan

Brian that is great news!
It's awesome to hear of great people doing things like that! Especially these days when it seems that everyone is only concerned about the all mighty $ 1st, then anything else after word!

FWIW I too have been blessed twice this past week with awesome offers from 2 great busnuts who are trying to help us weather out the tough times! (more details and proper credit where credit due later!)
;D  BK  ;D

Bryce,

I have kept up on some of your posts. Not had very good luck lately, have you  :( Sounds like you are due for a break  ;D

Things usually have a way of working out. There are definitely allot of good people on this board.

Good luck,
Bryan

Clifford and Bryan;

Great to hear about a new source for parts with good people. I need to take mine out in the next two weeks or so and clean and service it, it's not working at this time. I bought a new injector nozzle from Nick last week ( what a great guy to do business with ) now I have to find the time to do the work. I have watched this thread with great interest as you may have guessed.

Thanks

Don

WooHoo! It works  ;D At least it is putting out a flame. I am guessing it should be more of a jet type flame? Is this how it is supposed to burn? Here is a video of it running. I took a single pole relay off the old control unit and put it on the new one that John sent to me.

Webasto DBW 2010 (http://www.youtube.com/watch?v=w6O9IttfaKw#normal)


Thanks,
Bryan

I bench tested mine also (without the blast tube).The flame I had was more or less a ball of flame....I think if I had put on the blast tube,it would have looked like your flame.

Our two units certainly sound similar.

And my 'no start in cold weather' problem was rectified by using the pre-heat element for about 15 seconds or so before firing. I spoke with John today, and he highly recommended the nozzle-preheat especially if the temp is below freezing. It fired up at -30 on the first try after pre-heating.

Im gonna retest tomorrow when it goes to -34. Brrrr.

Hope the rest of your install goes well.

Mark

You must be pleased that the weather is cooperating so well for your testing Mark.  If it was warm now you wouldn't know whether it would work when it gets cold so it must be a great relief to have that worry removed.
;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D

I just got off the phone with Brian at Webasto. He is in Tech Support but was in the field for many years. He said it is not supposed to throw a flame out the end of the tube. Thinks the pressure may be turned up to high. So it looks like I need to take the old nozzle and make a fitting out of it to hook up a pressure tester.

The upside is that it ran  ;D

Bryan

Great news Bryan!!  Did the new old unit have any identifying numbers on the relays?

Steve

Steve,

Did the new old unit have any identifying numbers on the relays?

Only on the four single pole relays. They are still being sneaky about the double pole relay  ::) From looking at the cover for the new old unit it was from about 1997.

I think I will get a couple more relays from John and solder them into the old unit and then have a spare  ;D

Bryan

Hi Bryan,

Great Video... Looks like my shop with webasto flames every morning...

Do you know how to adjust the fuel pump? I kinda think you do making a PSI gague....

Good Luck
Nick-

Nick,

Yes I know how to adjust it, I just need to make a connection for a pressure tester. I was told by the Webasto tech to drill out and tap my old nozzle and put a fitting for a pressure tester. So I figure that is what I will do unless there is an easier solution. He thought the pressure was to high and that the flames should not be coming out the tube like it was so I need to adjust the pressure. I thought I would check it and if it is in the range I could use the .35 nozzle you sent me.

Bryan

Yes, drilling out an old nozzle, a comfortable length of brass pipe and the pressure gauge of your choice attached to the end is the way to do it.

Part of your PM of these units is to check fuel pressure, so you will use the rig again!

happy coaching!
buswarrior