I've got a 1994 XL Super Cab 4x4 with the 4.0L engine and 5-speed transmission. I don't drive this truck every day, it's just here because, frankly, everyone should have a truck(s) around for doing truck stuff with. It's got 237,000 miles and it's not the prettiest one around, but it is perfect for what I use it for. I do try and drive it to work once a week, and in the wintertime, it gets more use not just because it is 4x4, but because this thing has a heater in it that would melt the polar ice cap. I'm accustomed to being able to jump in it and go whenever I need to. However, a couple Saturdays ago, I jumped in it to go to the trash dump, and she wouldn't hit a lick. I tried jumping it off and couldn't, so I took the battery into town with me and dropped it off at O'Reilly's so they could test it for me. They said the battery was bad. So I put a new battery in it. I noticed when I was hooking up the terminals that there was a little spark, so I knew something was draining the battery while the truck sat all week. I left the ground cable off so it wouldn't run down the new battery until I had time to work on it. Today, I tried to trace down what the problem might be. I opened up the fuse box and started removing the fuses one by one and testing for the spark at the battery. I detected no change until I got to the big 20-amp circuit breaker #12. With it pulled out, there wasn't as much spark, hardly any. My owner's manual says that the circuit breaker is for the cigar lighter, flash-to-pass, and power lumbar. Well, my cigar lighter socket has no lighter in it, and I have no power lumbar. Since I still had a small spark at the battery, I started over at number one with the #12 circuit breaker still out. Luckily, the first fuse I removed (#1) produced no spark whatsoever. The #1 fuse is 15 amps and it controls the dome lamps (no bulb in it currently), power mirrors ( I don't have power mirrors), and the radio memory (I have an aftermarket radio). So, with the #12 circuit breaker and the #1 fuse out, I have no spark at the battery terminal. Anyone care to speculate where/what the problem might be? THANKS!!

 

is it actually draining the new battery?

i ask because it sounds like your chasing a drain just because of the spark, but i always (well, many times) get a quick zap when i reconnect.

 

I expected a small spark because of the radio, but not as big as the one I saw. I would've been ok with the smaller spark I saw after I pulled that circuit breaker out. I left the CB and that one fuse out and left the battery connected last night to see what happens. Next, I'll probably put the fuse back in and try it that way, just to see if the battery gets drained. I'm in no big hurry.

 

Might be helpful to know what the store found was the old battery failure cause. Was it not able to be re-charged, like a shorted cell that was causing it to self discharge, or was it a badly sulfated battery that wouldn't pass the load test ???? How old was the battery?

Does the Aftermarket radio have a tape player in it & if so, does it have a tape stuck in there??? If it does, the tape motor may not be turning off & that'll draw enough current to pull the battery down & cause more spark when the B- cable is hooked up.

If you suspect excessive parasitic draw, from things like aftermarket ad-on's, or something not going to sleep, or a courtesy lamp not turning off, or a system not timing out & turning off, or leaky alternator diodes, turn all interior items off, disconnect the B- battery cable & perform a parasitic current draw test with your multimeter that to be safe, can measure 20 amps of current. Connect the DVM red B+ lead to the disconnected battery B- cable & the DVM B- lead to the battery B- post, turn the meter on & monitor the current it reads over time, say 30min to an hour. After a period of time, as systems time out & go to sleep, the current will drop & stabilize. At that point it should not be drawing more than 50ma current draw. It sounds like you've narrowed down your suspect list by pulling fuses, now you just need to accurately measure the current draw to see if its excessive.

If you don't have, or can't borrow, or come by a multimeter to perform the current draw test, you could run this puppy by your favorite trustworthy auto parts store & ask them to perform a system electrical output & parasitic draw test, that can check the alternator for proper charge output & its diodes for excessive electrical leakage & the vehicle electrical system for excessive parasitic drain, with their electrical system tester. More thoughts for consideration, let us know what you find.

 

Thanks! Lots of good ideas there. As soon as I can figure out something, I'll report back. I was somewhat leery of that battery test deal. The best way to sell a new battery is to claim the old one is bad. I'm not accusing anyone, I'm just saying there's opportunity there. I have no clue what the old battery's issue was. I can borrow a multimeter from work. I'll see what kind of information I can come up with.

 

for what it’s worth, you can buy a test light that displays voltage. handy to keep in the car. simple to use

 

Thank you, seville! I'll take a look at it.

FWIW, with the #1 fuse back in, the truck set for a day+. I drove it to the trash dump yesterday, no problems. I haven't put that circuit breaker back in yet. Still haven't had time to do a multimeter check.