Electrical Problems, I have a short somewhere, Possible Solutions Options

[Cutrara]

Since Monday, a short somewhere in my wiring has been draining my battery (No, it's not the battery or alternator, I had them both checked) I took my car to get inspection/emissions and had them check it. He said the alarm was draining more power than it should. I pulled the alarm brain and disconnected the constant 12+, and ground wires from the alarm harness, and it's still draining. I have work all weekend and school all next week. I've designed a battery kill switch to cut off the battery as a temporary solution until I can diagnose the wiring problem over Christmas break.

Here is the kill switch I've designed:


Does this look OK for the application I'm using it for?
Would you improve anything?
Do you think something is shorting out?
Where do you think the short is?

Thanks,
Alex Cutrara

This post has been edited by Cutrara: Dec 17, 2005 - 4:00 PM

[RocketScott]

Unless you get a big enough relay you'll burn it out. Running all of the car through a single relay might not be a good idea anyway. If you just want to disconnect the battery you can get a connector that goes on your battery that has a big knob on the top you just unscrew to disconnect it. Look where the battery cables are at your local NAPA/Autozone/Big Earl's Car-o-Rama.

[Cutrara]

Actually, I'm not running the whole car off of it. On top of the positive battery terminal, theres an extra set of wires that powers the interior. Since I believe my short is somewhere inside, I think this will do the trick. If anyone knows what I mean, Do you know what Amp Relay I'll need.

[Dr_Tweak]

What you need to do is locate the drain, not try to fix it by adding another circut in. Take your key out and make sure all the lights and whatnot are shut off, then take a circut tester light and put it between the positive battery terminal and the cable. Then go to your fuse boxes and pull one fuse at a time. When the light goes out, you found the circut that is draining power. Now trace the circut out until you find the short.

-Doc

*edit* If you do decide to run a relay, you're going to need a 100-150 amp main power relay. You'll probably have to order it.



This post has been edited by Dr_Tweak: Dec 18, 2005 - 12:05 AM

[Cutrara]

Ok, I can't afford to be without a car for much longer. I'd rather not run a relay kill switch if I can avoid it. I connected my test light between the positive battery terminal and positive battery post on the battery. I pulled every fuse, under the hood and inside the car, and the test light stayed on. I disconnected and/or pulled every electronic device I've installed, including my alarm.

My brain is fried from working on this for days. Am I missing something? Maybe a relay is stuck open?

This is most likely irrelevent, but my starter is on it's way out. I've ordered a new one and it will be installed on Friday.

Thanks for your help,
Alex Cutrara

[TwistedmindZ]

Ok i'm an installer for car stereo shop, I've seen some dumb installer put the start disable relay on the constant so it drain the battery every time the alarm is armed, you have to make sure it's connected to ignition. also try running a multimeter in series to read amp draw between different fuses, check to make sure alternator wire not touching ground (had many people have that prob). also you wired the relay up correctly you just need to find something like a 100 amp relay most stereo shops only have 30-40 amp. Hope that helps

P.S. make sure battery is still good everytime it drains all the way it cuts battery life in half.

This post has been edited by TwistedmindZ: Dec 21, 2005 - 3:28 AM

[Cutrara]

There is no alarm in the car now. This makes me so angry I can't figure this out. I've pulled every fuse, and still, my test light stays on. I wish some more people could help me on this.

[TwistedmindZ]

also i've noticed most often shorts happen in constantly moving areas so check both door gromets for broken or pinched wires and the tailgate. also test lightstays on what? when you connect to what? also let me know if you had the battery checked lately.

This post has been edited by TwistedmindZ: Dec 23, 2005 - 2:05 AM

[Cutrara]

Its a brand new battery, but I even had it checked last week. It was fine. Dr. Tweak told me to take off the positive battery terminal and put a test light between that and the battery, and pull fuses. When it goes off, you found the circuit thats draining power. I pulled every fuse and it still stays on, which leads me to believe the short is somewhere between the battery and the fusebox. I'll check the moving areas, but I don't think the short it there, because those areas are fused, right? Is it possible that this is not a short and something else thats draining power? Thanks a lot man.

[TwistedmindZ]

hmm check for bad pin switches that is also a leading cause in drainage because it would have interior light on maybe at intermittant times. so try disconnecting the pin switches for a day or so and see what happens (just unscrew them and unplug them). with that test light thing you mentioned earlier it wouldn't make any sense to pull fuses because as long as the main 100 amp fuse is connected it completes the ground to the alternator/starter so it should always stay on anyways as long as it completes the path to ground and only way that it doesn't is if it is disconnected at the main fuse. Like i mentioned earlier try pulling out various fuses and putting a multimeter set up for reading amp draw and the 2 probes in 1 on each side of the fuse slot. If it reads more than an amp in certain fuses that could be the reason for the drain. If you follow that last step you should be able to figure out your problem. Let me know if that helps if not i'll think of other stuff but as far as i know if any accessory is drawing any current at all it should show up on the multimeter. this must be don't with ignition off and key out. there are 2 reasons a battery would drain besides having a bad cell 1st is grounding or getting pinch slightly (enough to drain power but not blow fuse (like a cigarette lighter when you push it in it heats up but doesn't affect the cigarette light fuse)) 2nd is something is defective and is either staying on after car off (ie. doorpin, relay not closing, could even be defective radio that drains too much for memory although rare). check all alarm connections make sure they taped up good or crimped good with no strands poking out. if you have amps check for loose strands in cables.

This post has been edited by TwistedmindZ: Dec 24, 2005 - 5:19 AM

[Cutrara]

I pulled all of the main fuses, and used my test light. I found that the EFI fuse is draining the power. Thank you so much, I didn't realize I needed to pull the main fuse. I tried testing the amperage with my multimeter, but it's brand new and really complicated and I didn't read the directions yet.

I suppose I'll look at some of the EWDs on CelicaTech to see where all the wiring is for the EFI circuits, to try and locate the short. Where do you suggest I look first? I'd like to have this fixed within the next few days, but if need be, can I just temporarily put the EFI system on a relay activated by the ACC or ON?

[TwistedmindZ]

i think that should be okay i don't think the efi drains more than 15 amps so a regular relay should be fine you might just need to know when to turn it on it should wires up like you had in the first diagram. I don't know too much about electrical under the hood so someone else would need to help you out with the actual efi.

This post has been edited by TwistedmindZ: Dec 25, 2005 - 2:15 AM

[Cutrara]

I think I'm just going to have the "ON" circuit activate the relay, so when I turn on my car, it turns on the EFI circuit. Unless, someone can tell me what to look for in the EFI circuit, I've looked but can't find anything out of place.

Thanks a lot for all of your help.

[Cutrara]

Ok, I was wrong about the EFI fuse. I pulled it and let the car sit overnight. The next morning my battery was dead. The battery is good. I did some more testing and found that the drain goes away when I pull the following things:

Disconnect Alternator Ground (The plastic case was broken on the fuse, and I didn't want to risk breaking it the fuse) If the alternator gets ground from anywhere, my test light turns on.
Pull 60A Main fuse under the hood
Pull EFI fuse 15A under the hood
Disconnect Alternator +
Pull Door 30A fuse inside car

My guess is that the short is in one of those circuits and the others are creating a false-positive by bridging a circuit.

Additionally, when I turn my car to "ON" now, my wipers are activated on the low speed.

Your help is greatly appreciated. Thanks.

This post has been edited by Cutrara: Dec 27, 2005 - 10:12 AM

[Cutrara]

Bump

All I need is for someone to tell me which circuit it seems like the short is in and I can go about fixing it. I just can't seem to find it.

This post has been edited by Cutrara: Dec 28, 2005 - 8:03 PM

[Cutrara]

Bump. Damn it

[RocketScott]

We can't really diagnose your car online and give you a precise answer. By your last post you've narrowed it down to just about everything. Your wipers coming on is a good place to look. Take it out and clean the switch. All those cicuits in your last post should be checked individually if possible. Are you saying that the only way the battery won't drain is if all those circuits are disconnected?

[Cutrara]

Are you saying that the only way the battery won't drain is if all those circuits are disconnected?

OK, it seems like the battery won't drain if the Door 30A fuse and EFI 15A fuse are disconnected. I charged my battery (almost to full) with a clamp on battery charger, and pulled those two fuses. I tested the battery periodically with my multimeter. In 9 hours, the voltage dropped .7V.

I will try cleaning the switch for the wiper switch.