Batteries again!

[Blacksheep]

On the way to Arcadia, my low voltage light suddenly came on but only after I had turned on my running lights. When I turned them off, the light went out. All was good until going home. On the way home, no lights on and about 45 minutes into the drive, the low voltage light re-appeared briefly and then when almost home it stayed on. Not only that, the trans would not shift the way it was supposed to. It shifted Up, Down, Up, Down, while accelerating! I contribute that to, again, low voltage!
Made it home and checked the voltage in each battery and then on the 24v leg of all 4. Each battery was 12.5 and 12.6 and across the 24 leg it read 24.6. Not high enough so I figure I will get new batteries today which I did! When they checked the old ones, they found that they were very dead and with a rating of 950 cca, they had roughly 30. So, they exchanged them with a whole fresh batch all from the same date code.
Now I put the new batteries in and check the voltage on each one prior to hooking them up. Each one read 12.5 and 12.6 (2 each had same reading) and I contribute that to sitting on the shelf. After hooking them up and starting the engine, I re-check the voltages. SAME as before! I turn on some lights like running lights and bay doors open and the voltage dropped a point! 12.4 and 12.5.
I went and looked at the voltage regulator and found that sometime prior to my purchase it has been replaced. It's a delco-remy 24 volt adjustable regulator model number 1118447. I tried turning it up a bit but it made no difference! I suspect the regulator is not doing a good job.  I hope it's not the alternator but if it is, I will change to less expensive Leece-Neville at that time!
Any thoughts?

Can someone explain in detail how to check the regulator other than what I have already done?

Does anyone have a source for this regulator?

Thanks...
Ace

[Sojourner]

To test alternator

Engine stopped; Master off.
Remove wire "F1" off the "FLD" terminal on the alternator. Meter the resistance of the "FLD" terminal. It should meter 3 to 5 ohms of resistance.
Open....Change out the alternator (Open field circuit)
Shorted....Change out the alternator and the voltage regulator. (Cooked field circuit due to regulator)
Yes....Field circuit is OK but the next step with the Engine stopped; Master off; Main disconnect on.

Remove wire "R1" off the relay terminal on the alternator. Meter the voltage of relay terminal. It should be less than 1.5 volts. The less the better.
Yes....Means diode is OK
No....Means one or more diodes is shorted. Change out the alternator.

Load test for winding and/or open diode test. Engine running; A jumper between "F1" (off the "FLD" terminal on the alternator) to DC positive terminal on alternator. Caution...never leave it connect more than 15 seconds or you can over heat the field and the main winding. It should meter over 30 volts on 24 volts system or half of that on 12 volts system.
Yes....Means it OK
No....Means Change out the alternator.

I do not have a Prevost manual to follow their schematic for more information about what with the relays before regulator.

FWIW

Sojourn for Christ, Gerald

Delcotron 50 DN Alternator Service Bulletin 1G-258

[Blacksheep]

Jerry, thanks for the information and I should have stated that I already had the delco site you provided. What I didn't see on the site was a pdf info sheet for the regulator. I saw sheets for internal regulators buit not external.

Thanks again...
Ace

[muddog16]

Ace, I'm sure you have a link to the Prevost Maintenance site, they have drawings online for every Prevost made you can download any drawing you need if you have a customer number........!  The customer number is free.......just use your vin number and apply, I've found lots of information there!

[Sammy]

Ace, a good truck parts house should be able to get you a regulator, maybe a NAPA store?- if it's bad.
I buy 'em from my rebuilder,MCI,or Prevost Parts.
Gotta make sure that there is 24v at regulator (POS) or (BAT), waiting to be delivered to the Field terminal of your alternator. Make sure there is a good ground too (NEG), if you have that terminal on your regulator.
Might have a relay that controls voltage to regulator.......
Send me the 10th digit and last 4 digits of your VIN, I'll check schematics for you.

[Blacksheep]

Muddog yes I'm aware of all that but not sure if I need to go that route just yet. Still diagnosing actuall items before I get into wiring!

Sammy the 10th digit is "N" and the last 4 numbers are: 1232

Ace

[Sean]

Ace,

Do you have a battery isolator in your coach?  If so, carefully check to see where the sense lead from the regulator has been routed.  It needs to be on the + terminal of the coach batteries for proper operation when under way.

-Sean
http://ourodyssey.blogspot.com

[Sammy]

Ace,make sure there is 24 volts at the BAT terminal on your voltage regulator with bus running. IF NOT -  your coach has a Field Relay - R3. It is supposed to be located in the rear junction box.You need to make sure has 24v on Term 87 of R3.That's battery voltage waitingto go to the BAT terminal of your voltage regulator.
You should also make sure that field relay R3 is being energized (24v) on Term 86 and there is a good ground on Term 85.
Disconnect BAT wire from voltage regulator(with bus shut off), check continuity from that end of wire to Term 30 of R3.
Here's the diagram.........http://prevostparts.volvo.com/technicalpublications/pdf/d060688p1c.pdf
My diagrams start with P300, so I went online too. Hope this may help you with your troubleshooting.

[Sojourner]

There you go....Ace!

Thanks for all you but nuts servant to make it possible for Ace getting lending hand of lean suggests. You all help me to try to be on top of anything I have no information on. And I do Thank you.

Muddog16's suggestion about we need VIN number to get online technical information.

Sean's suggestion is important...can be incorrectly connect wrong by previous owner.

Sammy suggestion is very important about R3 (NC) to be de-energize so it complete the circuit for 24v power to regulator. And it could have bad contact points in relay.

Sammy sends the drawing of most of the H-40 chassis wiring schematic. Very helpful indeed.

FWIW

Sojourn for Christ, Gerald

BTW...If you ever need to replace that old old old fashion voltage regulator, get the new solid state voltage regulator. All new buses with Delcotron 50-DN alternator are using the new state of art regulator. Part number is 10503805 or model 19020411 for 24v version.
They cost about $200 but I paid $17.97 on E-B at "Buy-now" with free shipping. He out of them now but if you ask them when more will come in or never? ?
10503805 Solid State V. Regulator

Another BTW...about changing to smaller alternator from 270 amp version. Make sure your aware that whatever inverter you are using while traveling or fast idling, that it can be capable handle all your 24v or 12v needs without being at it alternator output's limit so it would not break down too quickly. It much more reliable to have the reserve capacity of 20% or 30% over your common heavy charging demand.
After all about getting good use alternator at salvage/recycle store...a common class 8 truck use smaller alternator, never use as must current load as motorhome with 2 or more A/C and charging house-battery from over night used.
Also having power loss to turn the large 270 ampere alternator is about equal with other HD lower ampere such as 160 amp air cool version. In other words, if both were charging 160 amp...the power requirement is about equal. Belt drive requires more power than gear drive while charging at 160 amps.

[Blacksheep]

Thank you everyone for the replies to the problem which I might add is NO MORE! HOORAY!!!!!

Sammy, I think you for taking the time to find and send me the diagram. Here is what I did! Since my laptop is not presently hooked up to my printer, I copied the information and detailed instructions and sent it to my email which I received on my blackberry. I took the phone out to the bus and proceeded from there. When I started the bus, nothing had changed from this morning. I then went to step one and checked for voltage at the regulator. NONE! I then went and located the field relay which on my bus was numbered R3 just like Sammy and the diagram said. It was easy as it was the first in line! I checked the voltage there and found I had 24 volts present. Before I got into checking continuity on the wire from the regulator to the relay, I decided to just try a spare relay I had that was taken out of a slot that I know I didn't use. After replacing the relay, I started the bus and both 12v and 24 v gauges on the dash PEGGED. I shut the bus down and went and decreased the adjustment on the regulator which was ALL the way maxed out. I DID adjust that yesterday but only about the thickness of a screwdriver and didn't realize it was as far as it could go. Anyway, after decreasing the adjustment, the dash gauges read normal so I went and checked voltage directly on the batteries but first I turned on headlights and I already had some bay doors open with bay lights on. The batteries checked out with 25.9 volts across the 24 leg and 12.9 on each battery individually. I decreased the regulator even a tad bit more to where the reading is 25.6 and 12.7. I turned the lights off, no change! I turned them on again and they even seem to be much brighter. After shutting the engine OFF, turning all lights OFF, shutting all bay doors, the batteries seem to be fully charged and holding steady at 25.5!

I know this may not be the correct way in fixing a problem but it IS fixed for now anyway!

THANK YOU BUS NUTS!

Ace... FULLY CHARGED!!!!!!!

[Blacksheep]

UPDATE:

Last night I usually plug in my on board battery charger/maintainer but purposely neglected to do so just to see if the batteries would drain down overnight like they normally do. To my surprise, when I checked the voltage this morning with engine not running, no lights on, the batteries actually stayed charged. There was a slight change from the 25.6 when I put it to bed to 25.7 this morning.
My next question is this. Could a relay which is the only thing I changed, be bad, with a possible short, and cause a steady drain on the batteries?
What a difference charged batteries make with lighting! I didn't think my new LED's could get brighter!

Ace

[Sammy]

Ace, happy to help. Sounds like your bus was not charging because R3 was not energizing properly across the coil side,or contacts were not closing to allow 24v to get to your volatge regulator.Doesn't sound like a short circuit.
I would recommend to set the charging rate to at least 27.2v on the 24 volt side and 13.8v on the 12v side. To do this properly you need to start your bus,put it on "fast idle" and put a "load" on your factory charging system. When I put a load on a system I turn on interior and exterior lights and the HVAC system.
I then make very small adjustments to the voltage regulator while checking voltage on 24v side and then the 12v side.
After adjustment is made, shut off load,turn off fast idle ,keep engine running and make sure charging rate is still good.I have had excellent results with this method on many non-converted motorcoaches.

[Blacksheep]

Sammy thanks again! Let me explain the reason why I set the voltage like I did. First off, the manual states to set it as you said but that was for a seated coach with many more accessories than what I have NOW! In other words I don't have the bathroom fixtures, isle lighting, seat lights, map lights, step lights, fans, blowers and HVAC. It all has been either removed or completely disconnected. Only lighting I have that is original is head lights, (low and high beam) running lights front side and rear and the rear engine cover lights have been changed to LED's. All the bay lights are still operative as are the dash lights and gauges. So as you can see, I didn't see the need to have the batteries be charged at the higher rate. I may be wrong and correct me if so! As it was, I was afraid to run in the dark because the head lights never looked bright. My friend has an identical coach that he too converted and when he checked his voltage sitting idle with nothing on and engine off, it was 25.6v. If you think the coach charging rate still needs to be set higher, please explain why and I will pass the info on to my friend as well!

Ace

[Lin]

Ace,

Didn't you say you put in new batteries?  Could that be the reason they hold a charge better?

[Blacksheep]

Lin it seems I always have had new batteries. It appears that I was the dumb one in thinking it was always the batteries and kept replacing them, hence always new! After about a year things would always go the way they recently did with the exception of the warning light and the shifting problem! I thought I would finally go after what was causing me to think the batteries were bad by starting with 4 fresh ones and when they showed a no charge situation it was time to look deeper!
I really feel the culprit has been found and fixed. And byu the way, after sitting over 24 hours there has been NO drainage at all. I'm still curious to know if a bad relay would cause the batteries to drain like they were because before, by now, the bus would not start and the new batteries would be dead! I haven't changed anything but the R-3 relay.

Ace