Generator Battery Charging

[Mark Johnson]

I have an 88 PT 40 WB and the generator battery only charges from the
engine alternators. Shore power and generator power don't do it unles
I hold the "link batteries" switch. Does anybody know if one of the
two chargers in the back is supposed to take care of the generator
battery? Could one of the two be inoperative? Or is there a third
charger somewhare dedicated to the generator battery?

Mark Johnosn
88 PT 40 WLWB
Wasilla, AK

[Ralph L. Fullenwider]

Mark:

Two different things are possible on your Coach.

1. the battery tie switch on the dash, is it a left/righ/center type? if so
leave the switch in the center position.
2. There is a 1/2 wave charging diode for the gen battery. Some are located
in the next to the last compartment on the curb side. Then they are also
placed in front under the bumper on the drivers side. Check the diode for
forward and reverse continuity, ohms will pass one way but no the other.
Also there is a solenoid in that same area and should be a fuse block with
a glass fuse ( some Coaches have it some don't.) Finally check the ground
to the solenoid and also check the voltage at the diode when on shore
power. You are looking for 13.1 vdc to 14.2 vdc at the diode. The norm is
about a 1 vdc drop in voltage across the diode.

Oh, one more thing, on the outside chance of some one placing a 165 amp
battery isolator in your Coach, not factory installed, you might look for
one, and if installed check for voltage across that. If you do find one,
the battery chargers and alt should be on the center post with the gen
battery on post C and the refrigerator on post A, but the battery isolator
is rare on Coaches above '86/'87? or so.

Safe travels,

Ralph and Charolette Fullenwider
Ralph's RV Solutions, Duncan, Oklahoma
http://home.swbell.net/rlf47/index.htm

At 04:42 PM 2/26/2006 +0000, you wrote:
>I have an 88 PT 40 WB and the generator battery only charges from the
>engine alternators. Shore power and generator power don't do it unles
>I hold the "link batteries" switch. Does anybody know if one of the
>two chargers in the back is supposed to take care of the generator
>battery? Could one of the two be inoperative? Or is there a third
>charger somewhare dedicated to the generator battery?
>
>Mark Johnosn
>88 PT 40 WLWB
>Wasilla, AK
>
>
>
>

[krminyl@...]

Thanks to Ralph, I finally got my genset battery charging to work properly.
The diode he described was part of the culprit, and I changed the circuit
breaker and the three solenoids in the charger compartment just to be sure.
Works fine now.

By the way, that diode looks like a 1/4" bolt or insulated stud, with a nut
on one end and a solder "loop" on the other...each end has a 12ga wire
attached to it. Kind of hard to find if you don't know what to look for...mine
is
attached to a aluminum plate, facing out toward you, as you open the battery
charger compartment door (that's the way it is on my 86 PT...your's could be
different).

Good luck (and thanks again Ralph...three yrs later)

Kevin McKeown
Yorba Linda, CA
1986 38' PT


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