battery transfer relay?

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revpol

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Oct 16, 2012
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I have a 2000 Amer. eagle d.p. and have been trying to find the batt. transfer relay. It shows on my dash volt meter that while I'am driving there is little to no charging going on but if I push the mom button I get a charge and sometimes it lasts for a while. If I start the gen it also shows a charge. I've used a volt meter on the batteries(house & chassis) and it shows 15volts. so I'am thinking that possibly the transfer relay has bad connections? I've allready cleaned all the batt. conections. First fancy dp and I'am kind of lost on where everything is.(buttons,switches all over the place)  revpol
 

Gary RV_Wizard

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The transfer relay does not involve the chassis battery - it's purpose is to switch between generator and shore power sources.

The chassis battery is connected more-or-less direct to the engine charging system (alternator) and to the starter motor. Does the engine crank ok when starting?

The fact that the Aux Start switch brings the voltage up means the relay that connects house and chassis 12v systems is working as designed. Ditto for generator power, which provides 120v power to the house charging system, which in turn can charge the chassis battery by internally engaging the Aux Start relay. The same things happens when on shore power.

It sounds to me as though your engine alternator is failing and the only charging the chassis battery receives is from the house charging system.
 

Jammer

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I agree with Gary's troubleshooting assessment.  Alternators fail fairly often.  The diodes fail at the junction because of heat.  Usually when they're first starting to fail they'll more or less work while cold but quit producing any output after a few minutes of driving.

Anyway, the thing you're asking about is usually called a battery isolator relay, and I think maybe Gary meant you were asking about the transfer switch.

I don't know where the battery isolator relay is on your rig but you can usually find them with your ears if you have someone else push and release the button on the dash.  Just listen for the clunk.
 

Gary RV_Wizard

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The isolation relay is the same one that provides the momentary "Aux" start function and he already has shown that works. Besides, the chassis battery is on the alternator side of that relay, so should charge from the alternator whether the isolator works or not.
 

revpol

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Oct 16, 2012
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thanks for the input. was I was hoping for was a possible bad connection on the alt. side.  I just bought this unit a short time ago and it has very few miles (just over 40,000). there where some very green connections on the batteries so I cleaned them all up but I couldn't hear the telltail click of the relay. I will have to get my meters out tomorrow and check the alt. out-put.  thanks  Revpol
 

seabreeze331

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revpol
My 2002 Eagle had the same problem. I have the Heart Source Manerger. All my transfer controls are in the BCC in the aft compartment with the batteries. My problem turned out to be corroded wires in the big plug that goes from the fuse panel (under the step) to the firewall. There were other wires not making good contact and a lot of my troubles went away when I repaired the wires by by-passing the plug. If memory serves, the bottom plug has the 12V wire that sends the signal for chargeing. Listen for a chirpping sound to locate the relay.
My dash gage wouldn't show the altinator charging but it in face was so you're ok that it don't show on the dash but it sure is annoying.
Kevin Mallory is the top dog with the Heart Source. I'm not sure of his contact but there are a kizillon folk on the forum that does.
Good luck.
 

revpol

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found the relay then checked for alt. charge. guess I'll be putting in a new alt.  thanks : revpol
 

Gary RV_Wizard

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Leave shore power disconnected, generator off, and start the engine. Turn on the head lights and then check the voltage at the chassis battery. If less than 13.3 or so, your alternator is not delivering charging current. If the battery voltage stays stable at 13+, then the alternator is probably ok and the problem is bad wiring. Note: you may have to run engine at a bit more than idle to handle the head light load.
 

revpol

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Oct 16, 2012
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because the house batteries where still charged I had to isolate them from the chassis batt. to run a output voltage test.  If i was able to reach the alt. safely I would of just checked from the back of that. My voltage reading never increased so I'am sure that it is the alt.. All the connections looked good. I'am just surprised that only having so few miles on the unit that the alt. would go out.  thanks..  revpol
 

Gary RV_Wizard

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Lack of use can be a negative for anything that has wire windings and control circuitry, which includes alternators and generators. Moisture can build up and cause damage when not in use, whereas regular use keep them warm and dry.

And I'm sad to say the Leece Neville alternators used in both Spartan and Freightliner coach chassis don't have the  best track record for longevity either.
 
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