'99 Ram 1500 battery drain in 10 days

you say the battery is only a few years old. how many is a few? down here in the south where we get periods of 100 degree days it has a tendency to kill batteries during the heat. what is your climate like? i would figure out how old that battery is and test it before i went looking for more complicated issues. if the battery checks out then dig deeper. michael

The battery is about 2 years old, the climate here is almost perfect except for the wind. We complain about the heat when it reaches 90F and the cold when it reaches 50F, (yet we don't complain when the winds are at 35+ MPH from noon to sunset, unless it's a "cold" day) so I think the battery should be good, but I don't know how long it sat at the autoparts store before I bought it. I had a 6 year old battery in my Scout II tested while I was looking into starting problems with the Scout and it held 650 amps (the battery's rated CCA) for a minute with no problem. I realize the age and performance of that battery doesn't translate to this battery.

I also recieved some good information about the ignition off drain (IOD) this truck should experience and a few tips on how to trouble shoot, so I think I'm armed with the knowledge I need, now all I need is the time.

If I find that the IOD is within parameters, I'll have the battery tested.

punkin sez check for an open relay.

Dead Batteries

- punkin, May 15, 7:38 pm

Thanks, and Merry Christmas.

Put a DC ammeter in line with your battery and cable and see how many amps it's drawing and then disconnect one thing at a time until you see it drop significantly. Often times the alternator can have a broken diode that will suck the life out of a battery, and yet still charge the battery. Start with the alternator.

Go back to one battery for these tests, remove the stuff in between the two batteries.

Yeah, I did all that and found about a 0.7 amp draw unless I remove the IOD fuse (which seems high to me) and a 0.46 amp draw with the IOD fuse in, but the Seatbelt Timing Control Module unplugged. I think I'll just continue to pull the IOD fuse when it will be parked for a while.

Generally speaking make sure your test is done about 30 minutes after the last thing done on the vehicle (close doors, don't reopen them, etc.) wait 30 minutes then test. Some circuits will draw current for a while then shut themselves off after an predetermined interval.

Thanks. I know the CTM should shut off after about 2 minutes and the SCTM after about 30 minutes. The problem is my digital multimeter shuts off after 15 minutes, and my ammeter isn't sensitive enough to see a difference. I should get an old fashioned analog multimeter with the correct sensitivity. Everything is working (at least for now), so I've learned how to live with it.

Had a very similar problem ... if it's a Quad Cab let me know. I'll let you know what I found with mine.

Fred

Gotta ask, wtf does the number of doors have to do with it

It is a quad cab.

The quad cab has a motion sensor under the seat as the seat belts aren't anchored to the door posts.

There is a wiring harness under the seat that connects to the motion sensing device to lock the seat belts in case of collision.

The plug that connects this harness under the seat shorts and you have current flowing all the time.

If you would like to know how to fix this drop me a note.

Drop the j in the email address.

Hey Roy!

It has to do with the seat belt system they had to come up with for the quad cab.

Belts are not attached to the body but to the seat structure. They are electrically locked in a collision.

Fred

Maybe you could post it here, that way it will be in the archives for future searches...

Really! If this guy has the fix... Guess we need the jaws of life to pry the answer out of him. Ed has had this problem for a few weeks. I'm sure he would like to see it posred as well.

Sorry guys ... been very busy lately and truck is in storage.

I will go over there this week and get the info on which conductor on that harness that you have to cut and splice through. You have to bypass the plug or replace the wiring harness under that seat to fix this problem.

Fred

Hi Guys!

Finally got a chance to have a look at the truck in storage.

The fix is to splice the light blue conductor going into the multi conductor plug under the driver's seat. Cut the wire on both sides of the plug and butt splice it around the connector.

The problem is an internal short in the multi conductor plug under the seat that develops over time.

Sorry for the delay.