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View Full Version : 98 Ram -Fuel system Drains battery intermittently


DieselGrl
01-03-2010, 04:07 PM
This is the first time I've had to work on this truck, mine is a Diesel (Chevy) so I am hoping you guys can help me identify what is wrong with my gf's truck.

Here is it's history-
She bought it a year ago at an auction from Washington State University. It was used as part of their Landscaping/Maintenance fleet. It has only 56k miles, and she has only put about 1000 on it, so we don't use it alot.

When she looked at it, the battery was dead (Optima). They charged it and everything appeared to be ok. We drove it home (330 miles) and found that if it sat for more than a day or so the battery was dead. It checked out bad so we put a new battery in it last summer. We've used the truck a few times here and there with no issue over the last several months, maybe averaging once monthly.

Yesterday we went to use it and it was so dead it was like there was no battery connected.

I figure there is either a short somewhere or a bad part draining the electrical system. I connected up the charger and heard a clicking sound from the rear, I believe it is in the Fuel Pump assy somewhere. I am suspecting this is an ongoing problem we just hadn't discovered yet and is possibly very intermittent.

Does anyone know if there is a way to identify what the culprit is without dropping the fuel tank? I'm not excited about trying to heat the shop and tear the truck completely apart ... :(

mrjordan2u
01-03-2010, 04:40 PM
I'd check your alternator, then get a multimeter and check your fuel pump relay with the truck off and keys out. I'd start at the fuse box and see which is reading a charge.

DieselGrl
01-03-2010, 06:11 PM
The Alternator has tested good. ...plus the battery only dies while sitting off for a period of time, we've had absolutely no problems with this truck otherwise.

So to make sure I am clear, with the keys out/off, if there is any reading at all in those relays then that is the culprit of the drain.

I'll check it possibly tomorrow night or the next day. I'll be gone most of the day and won't be able to get into it.

Thanks for the suggestion!

Tbird100636
01-03-2010, 08:46 PM
The Alternator has tested good. ...plus the battery only dies while sitting off for a period of time, we've had absolutely no problems with this truck otherwise.

So to make sure I am clear, with the keys out/off, if there is any reading at all in those relays then that is the culprit of the drain.

I'll check it possibly tomorrow night or the next day. I'll be gone most of the day and won't be able to get into it.

Thanks for the suggestion!
The fuel pump relay is in the PDC (underhood fuse block). It is controlled by the PCM. The PCM is in the Right Rear corner of the engine compartment, next to the A/C dryer. It has 3 connectors. The next time the pump seems to be running, disconnect the PCM connectors (squeeze the tabs on the top and bottom of each connector). The pump should stop. This would indicate a bad PCM. Make sure first Pin 2 of the PCM connector C1 does not have power with the Key shut off. If you find any green corrosion on the connectors, they have to be replaced.

https://w05.dealerconnect.chrysler.com/service/mds2002/serviceInfo/en_US/br808077.gif

xxnshcxx
01-06-2010, 04:01 PM
Get a couple strong friends. Lifting the bed is easier than dropping the tank.