Bench Testing Webasto

[bryanhes]

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 
I will update you tomorrow.

Bryan

[bryanhes]

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  . 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

[Nick Badame Refrig/ACC]

Hi Bryan,

Is your unit 12v or 24v?

Nick-

[bryanhes]

Nick,

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

Thanks

Bryan

[Nick Badame Refrig/ACC]

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

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

Good Luck
Nick-

[bryanhes]

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

[stevet903]

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.....

[Nick Badame Refrig/ACC]

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-

[bryanhes]

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

[Nick Badame Refrig/ACC]

Control unit Bryan.

Good Luck
Nick-

[bryanhes]

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

[bryanhes]

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

[bryanhes]

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

[stevet903]

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..

[bryanhes]

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