Electrical short....I think

Ok so I was driving the other night and all of the sudden I started to smell the scent of burning electronics. I pulled over and cut the engine but could not locate the spot where the smell was coming from (but it was definitely from some where inside the truck. The truck started up like normal and I was on my way. At first I thought I must have fried the alpine amp im running under the rear seat. It was bound to happen because there is not much air circulation under there. It was late at night so I decided to go to bed and figure out what happened the next morning. When I went to start the jeep up the next day my optima yellow was completely drained... I’m running dual batteries with a painless wiring kit so I flipped to my second bat and started right up. So I have a short somewhere and I can’t find it. I then tried disconnecting all stereo equipment and bat still drained. Has anyone had a similar prob? Is any electrical component or wiring notorious for burning up? Somebody please help.

Try disconnecting the + cable from the battery and then connect an amp meter between the + terminal of the batery and the cable. It should show some amperage draw. Then start taking out fuses one-by-one until the meter goes back to zero. That will lead you to the circuit(s) that has the short. then you will have to trace the individual components in that circuit to find the short. Good Luck!

mr bill3 thanks for the reply, what amp meter would you recomend buying?

You can get small cheaper ones at places like home depot and the like. I would reccomend putting down about 30-40 bucks on a decent one at mabye Radio shack.Thats where i got my first Multi meter and ive been using it since 1993, still goes on.Sounds like, since you have all the stereo equip, you do things that would entail suture use of the multimeter. So theres even more reason to purchase a good one.
http://www.radioshack.com/product/i...1000/00004999&kw=multimeter&parentPage=search

damn, long link, but that one will suit your needs.
Fluke makes good meters, but they are highly overpriced.HIGHLY....
And remember that measuring current, or Amps. Which is the measurement of the amount of electrons flowing, has to be done in series in the circuit. Like mrbill3 said.you gotta disconnect the cable from the battery, then place the meter in the circuit.Good luck! Grounds are ususally a challenge to troubleshoot.

Trbocharg said:

mr bill3 thanks for the reply, what amp meter would you recomend buying?

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I think what he means is to connect, for the moment, a good Digital Multi-Meter (DMM) in series with the rest of the circuit (red lead to battery + terminal, black lead to cable connection.)

If you don't have a DMM yet (and just why not?) I'd suggest you make sure to get one that will handle, at the least:
Resistance/OHMS reading
Voltage (AC and DC - you'll find yourself using it to check household electrics as well...)
Current (this is the one that we're talking about here - your current reading will likely be in DC amps, and you should get one that can handle at least 5 or 10 amps. Higher is quite expensive.)

Useful additional ranges:
Temperature (*C and *F)
Transistor Testing (this can be done with an ohmmeter, but having the transistor check it easier)
Audible Continuity Testing ("Beep" circuit testing - usually at one end or the other of the Ohms range.)
Capacitance checking (not something you'll use a lot, but you eventually might, and you'll be happy to have if if and when you do.)

Here are some links to meters you can find at Sears for around $100 or less - they should be good quality (I've got a couple Sears DMM's myself, and use them a LOT more than I use my $800 Fluke!) and you should find something useful in there...

http://www.sears.com/sr/javasr/prod...00&subcat=Multi-Meters,+Testers+&+Accessories
http://www.sears.com/sr/javasr/prod...00&subcat=Multi-Meters,+Testers+&+Accessories
http://www.sears.com/sr/javasr/prod...00&subcat=Multi-Meters,+Testers+&+Accessories
http://www.sears.com/sr/javasr/prod...00&subcat=Multi-Meters,+Testers+&+Accessories

Alsol, walk in and see what they've got. It's worth checking your local Hardware store as well - they won't have Craftsman, but they'll probably have Fluke (damn good meters!) and will probably have Gardner/Bender as well.

I've found the Craftsman units to be rugged, and survive use well.

One last thing - if you have the option (this could happen at Sears, and whatever hardware stores you've got,) you might want to consider getting a meter with an analogue (needle) face AND a digital inset. The digital portion will be good for fairly precise readings, and the analogue has a much faster response to changes - which you'll find yourself needing...

5-90

I really appreciate you guys taking the time to help me out. I plan on going to Sears today to purchase my first digital multi-meter. Then the real fun starts... If I have any more questions while trying to find the short ill post them.

Thanks again
Adam

One thing to remember when testing. You'll always have a slight draw on the battery from the PCM, and radio. However it should be very small, and I don't know what it will be (I would think only a few hundred milliamps). I would suggest asking a mech at your local dealership if no one on here knows.

I found the short and it only took me about 20 minutes. I hooked in the multi-meter and started pulling fuses from the main fuse box under the hood. My first read out was 1.25 but this was with the under hood light on so I disconnected the light and I was getting a readout of .8
I then continued pulling fuses one at a time till I pulled fuse #16 which was a 20 amp yellow the read out then dropped to .01 ....Then I took out my manual thinking that this was just the easy part and the tedious work is yet to come in form of wire tracing for hours on end. But I got dam lucky!
#16 turned out to be the stock stereo amplifier which I still had hooked up to the rear speakers. I was almost right on my first guess. Anyways I pulled that turd of an amp out and gave it the home it deserves.
I’m a happy man once again with 2 fully charged batteries sitting under the hood.

Thanks to everyone that helped.

Sincerely,
Adam

Trbocharg said:

I found the short and it only took me about 20 minutes.

Thanks to everyone that helped.

Sincerely,
Adam

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Well Done!!! You solved your problem and more importantly..... You got a new tool:sunshine:

And thanks for posting your results. It always helps to see the results when you are searching a topic.