Alternator Problem??

[Gorlininc]

I have a 2001 Diplomat 38A. I was driving yesterday, everything was fine for 3 hours. The last 30 minutes of the ride strange things started. I was on cruise control at 60mph. The motor lost power and came right back. It did that several times. I noticed 1-the booster gauge took a dip to 10 then right back up. 2-my voltage was now about 13.5 when it's usually at 14.2v.

When I took the cruise control off. It worked fine. I had to turn my headlights on. When I turned on the parking lights my voltage dropped to 12.8v. When I out the headlights on the volt gauge went to 12.5 volts for a few minutes. Then it slowly climbed up to 14.0 volts.

I have 6 month old chassis batteries. I checked them with the engine off and shore power. I get 12.8 volts. That's not good.

My manual says I have a chassis battery maintainer. I have no clue where it is. I can't find it. I think if it is bad it may be dragging my power down while driving.

Anyone have knowledge or ideas??
Thanks
Rick

[crah]

Rick


Is your 2001 diplomat on the roadmaster rr8r chassis? I don't recall what year the diplomat went to that chassis, but I think your year was the rr8r. To the best of my knowledge, the chassis batteries are charged while on shore power-no maintainer or bird system for that year to the best if my knowledge. Your statement from the manual confuses me though. I may be wrong.

How long was it sitting before you used the coach?

[Dupdyke]

Take it to a shop that rebuilds alternators and have them run a check. If it is bad have it rebuilt do not replace it can start a real can of worms use what was put in at factory and rebuild.

[PyrateSilly]

It could be some wires in the main bay where the main panel is at that may be coming unattached. (ours were purple wires, hard to describe where they are, yea hard to imagine that 2 wires could cause so many problems)

It could be the alternator and if your voltage regulator is not part of the alternator it could be that too. (ours is separate and the plug on the VR is on the bottom and it was slowly sliding out, some zip ties to tie back and it was fine)

It could be something to do with your cruise control. (ours is Bendix and we had to call around for the part, almost had to just get a new cruise control but someone finally had the part we needed)

We've had similar and those were the culprits. So all in all besides some time the only thing that cost money was the part for the cruise control and that $100 for 2 just in case it happened again.

[crah]

Originally Posted by crah

Rick

Is your 2001 diplomat on the roadmaster rr8r chassis? I don't recall what year the diplomat went to that chassis, but I think your year was the rr8r. To the best of my knowledge, the chassis batteries are charged while on shore power-no maintainer or bird system for that year to the best if my knowledge. Your statement from the manual confuses me though. I may be wrong.

How long was it sitting before you used the coach?

I see that I had a typo. I meant the chassis batteries are NOT charged while on shore power.

[Jim_HiTek]

Originally Posted by Gorlininc

I have a 2001 Diplomat 38A. I was driving yesterday, everything was fine for 3 hours. The last 30 minutes of the ride strange things started. I was on cruise control at 60mph. The motor lost power and came right back. It did that several times. I noticed 1-the booster gauge took a dip to 10 then right back up. 2-my voltage was now about 13.5 when it's usually at 14.2v.

When I took the cruise control off. It worked fine. I had to turn my headlights on. When I turned on the parking lights my voltage dropped to 12.8v. When I out the headlights on the volt gauge went to 12.5 volts for a few minutes. Then it slowly climbed up to 14.0 volts.

I have 6 month old chassis batteries. I checked them with the engine off and shore power. I get 12.8 volts. That's not good.

My manual says I have a chassis battery maintainer. I have no clue where it is. I can't find it. I think if it is bad it may be dragging my power down while driving.

Anyone have knowledge or ideas??
Thanks
Rick

Sounds like 2-3 different things going on.

Loosing power: Check air filter and fuel filters. Some rigs have a fuel solenoid and if you were loosing battery power to it, it could drop out and give you your symptoms.

Voltage fluctuations: Bad connection, shorting out running light or headlight, vibration causing a loose connection, alternator bad or going bad, field voltage supplied by the ignition system dropping because of a bad diode, loose connection, loose belt, bad solenoid. First job would be to clean all the battery terminals.

After parking, and plugging into shore power, you should have 14V on your house batteries coming from the converter or converter/inverter if you have one of those. If not, find your converter and make sure it has 120V power, and it's CBs are OK.

Your chassis (starting) battery will not be charged on shore power UNLESS you have a Trik-L-Start, BIRD or similar system. Many RVs of that era did not come with them but had statements in the Users Guide that suggested it did...but for a long period it was an option. You'll have to pull your original build sheet to find out.

[Gorlininc]

Thank you for your replies

I have the rr8r road master chassis. I can't find a chassis battery maintainer although that's what the manual says. The voltage suggest that the batteries aren't being charged, although the 12.8v says they are fully charged. I'm thinking that the regulator or alternator is not working properly. A drop in voltage could effect the ECM on the engine casing the loss of power and the cruise control problem.
I also thought if the battery maintainer was faulty it could cause some problems. Well off the shop I go.
Thanks for your replies.
Rick.

[Gorlininc]

Here is the page in my manual. It doesn't say the maintainer is optional. Someone could have removed it I guess.

[crah]

Originally Posted by Gorlininc

Here is the page in my manual. It doesn't say the maintainer is optional. Someone could have removed it I guess.

Pretty common to have inaccurate info in the manual. Pretty sure your vintage did NOT have a maintainer. Wa your coach sitting for a while?

[Gorlininc]

No I bought this last May I have put 12k trouble free miles on it already. I know the inverter circuit. I never inquired about the chassis batteries. If they don't have a charger, then I'll get one. Although we never really sit very long. I guess the most is 3 weeks and the batteries can handle that easily.
Rick

[crah]

If you sit for 3 weeks, your chassis batteries will definitely drain down quite a bit from both parasitic draw and self discharge. Was it sitting for 2 weeks plus right before this drive?

[Gorlininc]

I drove it about an hour the day before this drive. All ran good, but wasn't high speed driving. Either way the drive yesterday was 3 hours before anything started and should have been charged. Right ?

[crah]

Originally Posted by Gorlininc

I drove it about an hour the day before this drive. All ran good, but wasn't high speed driving. Either way the drive yesterday was 3 hours before anything started and should have been charged. Right ?

Rick

It seems the battery charge may not be related to your problem but to answer your question, it depends. Simply only driving for that time is not enough to fully charge your batteries if it was parked for for 2 weeks. Especially if you repeat that pattern all the time. The parasitic draw on these things are quite high and I'm not sure if you are using your battery disconnect either.

When you were taking these voltage measurements, was your coach at idle or shut off? If it was running, then you shouldn't have had voltage drop by turning on the lights. If it was off, then the voltage drop is normal. Your 12.8 measurement may still have been a surface charge only. You might want to read up on the 12 volt side of life if you haven't already. Again this may not be related to your problem. You Amy want to double check your connections at the battery. Perhaps something came loose.

[LaZy507]

i dont know much about anything really, but a quick way to find out if your altn. is out...with your rig running,pull of the neg. battery cable. if your rig dies its your the altn....or thats the way we do it on cars/trucks. hope it helps man.