Hello
Since we got my husband a beater commuter vehicle a couple of years ago, our Ram has gotten little use - the occasional trip to the dump, pulling the horse trailer now and again, and the few trips we do each year to stock up on hay. Diesel is just too much $$ to use it casually!

In the last year, we must have developed a short somewhere because when the truck has been sitting for awhile, the batteries go completely stone-cold dead. We recently replaced the batteries though they were just two years old because they wouldn't even take a charge.

I thought I had fixed a possible drain when I discovered that my trans temp gauge wasn't working. I disconnected it thinking it was grounding out somewhere. Then we got the fresh batteries, and I thought we were good to go.

Today I went to start her up and she's stone cold dead again! I just don't have a clue as to where to look to figure this out.

Known issues, might be contributing:

* A/C no longer blows cold. We were going to take it down tomorrow to get that fixed along with some new tires!
* also have a fuel pressure gauge but that works fine
* transmission temp really climbs when going up the windy hiway to our town, especially when pulling a trailer. Once or twice I've actually had the check engine light come on when the temp reached the red zone on the gauge! This is another post!

I know it isn't good for these guys to sit for long periods, but we just drove the truck about 3 weeks ago, and brand new batteries going dead just doesn't seem right!

Sometimes when this has happened, there will be enough juice in the batteries such that when I open the door, a wierd chuttering noise occurs in the cab, don't know the source.

Is there anyplace on the chassis where known short issues occur commonly?

Help!

 

if the batteries were new an you just put them in an then let them sit, it is very possible they went dead!

 

Nope - we drove about 400 miles in a day on those new batteries, and then I used the truck on another day to haul some things in my trailer before it sat.

 

When the truck is running are the batteries charging, if not check the fuse in the PDC (fuse box under hood) the fuse furthest away and closest to the engine. If you don't drive it much and you move it around the yard a lot the batteries will soon die as they don't get recharged enough after starting.

 

Knowledgable teck needs to run a amprage draw test with engine shut down. If excess currrent draw, generally pull fuses till find problem circuit. Things like glove box light or electrical add on are causes.

 

Manual states that 21 days without starting will drain batts. Pull the IOD fuse in the underhood fusebox ( the one with the yellow sleeve around fuse, 15 amp i believe )

That should take care of the problem unless there really is a short.

 

I notice you pull a horse trailer, do you have a trailer plug in the box, if so is it just laying there? We bought a used car for my daughter and it had had electrical problems. It has a trailer hitch installed with a trailer plug just on about 3 feet of wire and this was just laying in the bottom of the trunk. Turned out there was a water leak and when it rained the trunk got a little water in there and would short the plug to ground.

 

You might consider a battery maintainer. About 19.99 at any auto parts store. Just clip it on, either battery if you have two, and plug it in. It will keep the batteries charges and excersized. it will actually put an occasional load on them to work them. I added one to my rv and it took care of all of my battery sitting still issues.

 

You have a current draw. If it were a short you'd have melted wires or a blown fues and then no more short. As dozer said, an ammeter needs to be connected inline and fuses pulled, other things disconnected, one at a time, to determine where the current is being used. The computer and radio memory/clock will soak up a little bit of current, and will eventually drain the batteries, but that should take 6 or more months with a normal draw and good batteries.

A cheap way to track this is to put a test light between the positive cable the the positive terminal of the battery. The light will glow and you can pull fuses/connections to see when the light goes out. The caveat here though, is the draw may not be large enough to make the light bulb glow, even though it is enough to pull down the battery. If this is the case, and you'll know immediately, then the only way to test will be with an ammeter.

Chris

 

The computer and radio memory/clock will soak up a little bit of current, and will eventually drain the batteries, but that should take 6 or more months with a normal draw and good batteries.


this would be true if they drove it everyday...it tends to drain faster when you dont run the vehicle!

 

"A cheap way to track this is to put a test light between the positive cable the the positive terminal of the battery"\

You will NEVER find anything with this. That light setup like that will stay on untill the battery is dead. There will be no fuse to pull that will stop it. A light will never test current draw. There will alawys be a trickly of current draw to the radio just to keep the clock and station memory. The ecm and pcm will probably always have some draw on it. The only way to test curreent draw is with an inline amp meter. Any decent digital volt meter will do the job. Connect it inline to do this test, but remember you will never eliminate all current draw unless everything that draws power is disconnected, and that's really not practicle.

 

Like I said, take it to a knowledgable tech and have a electrical draw test performed. The test light has a place in testing, but the unknowing will never get it right. If you must know, hook ampmeter to battery post and to cable. Now remove the cable from post and you never break the circuit. Otherwise you get a arc when reconnect and a big draw.

 

Traced this same problem, (took quite a while too!!) to the underseat connector body that feeds the
seat belt control module. It was shorting out between the B+ pin and the ACC pin leaving the accessory line on all the time.

Try turning your wipers on with the key off ... if they come on you have the same problem.

I cut the ACC lead on this connector and made a hard splice to eliminate the problem.

Fred

 

I had a similiar problem not long ago. What I had done was while tightening the nut on the cable from the alternator back to the drivers side battery, I touched the wrench to the exhaust manifold. It blew the 40 amp fuse that connects to the block fuse just to the inside of the under hood fuse box. Check this out. Mine would go dea within hours of putting a fullcharge on it.