Need to Understand

[itdave]

I have two things going on and I am not sure if they are problems or how to fix them if they are. First when I start my coach even after just an overnight stop I notice that if I am on slow idle the Volt gauge on the dash fluxuates between 12 and 13.4 volts when it goes to 12 my dash lights dim. After the coach has run for 10 or 15 minutes the gauge stay at around 13 volts regardless of engine RPM.

The second issue is the state of the house batteries after driving all day. As soon as I park and plug into shore AC or start the generator I am in bulk charge. This would not be too much of an issue except my kingdome will not operate on less that about 12.2 volts and my house batteries seem to be under that when I stop for the day. I thought the Alternator would charge the house battery while driving so long as the chassis batteries were at full charge. I know about the boost relay in the battery bay but I am not sure how to test it.

I don't know if the two problems are related. This started happening maybe a year ago it was not like this when the coach was new.

Thanks in advance for any thoughts

[Rex]

Dave, not sure about your coach, but my 01 Diplomat is first cousin to the Endeavor. It does not have the BIRD or other units that will charge the House batteries from the alternator. The House batteries are only charged by shore or generator power. I suspect that is the case with your Endeavor also.

That being the case, when you park overnight and use the House batteries to power your coach (no shore or generator power) it naturally drains them down to some point. Next morning when you start the engine and notice the Volt meter fluctuating, that is normal - but not good either. Best thing to do is start the generator and let it run for 30-minutes to bring the House batteries up so the alternator does not have to work so hard. Working it hard can often cause it to fail. If you ever notice the Tach giving rapid swings or not working as it should, that is generally an early warning that the alternator is about to fail.

[hdossett]

You didn't mention the state of you house batteries before driving all day. If they were fully charged in the morning, and low at the end of the day, they may not be holding a charge very well. Any load on the while driving?

If the alternator is weak and the house/chassis batteries are paralleled while driving, you may have a weak alternator and are using the house batteries to operate the chassis.

Not an expert here, just so random thinking!

Harold

[lonnie4801]

If your batteries are still weak after running all day I would look at 2 things:

1st - check the condition of the batteries. Since yours is an 06 it may be time for new batteries.

2nd - check the selonid that is in the battery compartment. It controls the flow of voltage from the alternator to the batteries. When it is bad the batteries will not charge when the engine is running.

Lonnie - 2007 Ambassador

[Diplomat Don]

itdave.....On my coach when you first start it and it's warming up, the voltmeter will drop suddenly, several times, for about a minute or two. I was told that this was caused by the heater rail for the injectors. Once the engine warms up, the heater doesn't come on anymore.

Your coach should charge both the house batteries and the chassis batteries as you drive down the road. The lowest batteries are sellected and charged first.

Some of the caoches don't charge the CHASSIS batteries when the coach is on shore power. You need to check to see if you have the BIRD unit or another aftermarket charger for the chassis batteries when on shore power.

From your description, it sounds like you have some bad house batteries. Charge them overnight and then have them tested. You can't test dead batteries.

[LewF]

Don is right on the fluctuating voltage on start up. Diesels have heaters that aid warmup during start up and initial run time. The voltage drop is caused by the heaters coming on. It should stop shortly after you start however - shortly being defined by how cold the outside temp is.

On testing lead acid batteries you can check the specific gravity of the electrolyte and tell a lot about the condition of the battery if you don't have access to someone with the equipment to test them otherwise. A charged reading would be about 1.25 and anything less than 1.1, after a long charge cycle indicates trouble. A quick internet search for lead acid battery specific gravity will tell you about the process and expected readings. You can get a specific gravity tester at most any automotive parts store. But most important as others have pointed out if your batteries are very old then they are probably toast.

One thing not stated here is that once the large capacity batteries are deeply discharged they take a long time to recharge, maybe longer than a days driving.

Lew

[ShapeShifter]

My rig does the same volt meter fluctuations described by the OP, but I don't have any of the other issues he describes.

Quote:

Originally Posted by Diplomat Don itdave.....On my coach when you first start it and it's warming up, the voltmeter will drop suddenly, several times, for about a minute or two. I was told that this was caused by the heater rail for the injectors. Once the engine warms up, the heater doesn't come on anymore.

This is a very plausible explanation for the fluctuations. Thanks for the information, I've often wondered what was causing it.

I've also noticed voltage drops (and dimming lights) before I start the engine, whenever the "Wait to Start" light is on. I presumed this was because of the heavy current drain of the grid heaters. I don't know why I didn't consider that there would be something similar once the engine is started.

[src]

I have an 06 Endeavor with the same problem. I'm at Wildwood and they said the coach is not set up to charge the house batteries when driving.

Where is that selonid in the battery box? I want to have them look at it.

Also, what is a BIRD?

[Luv2go]

Quote:

Also, what is a BIRD?

http://intellitec.com/PDF/5300362.100.pdf

[deadeye916]

Quote:

Originally Posted by src I have an 06 Endeavor with the same problem. I'm at Wildwood and they said the coach is not set up to charge the house batteries when driving. Where is that selonid in the battery box? I want to have them look at it.

Just wanted to note that my BIRD is in the drivers side front compartment. Here's a couple pictures...

[itdave]

I don't have that module. I was under the impression that the 06 Endeavors and Diplomats could charge the house batteries while driving but not the chassis batteries while connected to shore power. For the folks that have bought the device that is support to give up the ability to charge the chassis batteries while connected to shore power does scr comment " I'm at Wildwood and they said the coach is not set up to charge the house batteries when driving." have any relationship to the problems you are having getting the BIRD device from Mega RV?