I had my car running last week. Friday night before I went to my girlfriend's for the weekend I went to run the car for a minute on the way out. The car cranked a few times then died before starting. (AEM EMS usually takes a few cranks to sync before starting so that itself is not abnormal.) Tried to crank it again, no crank, still lights on in the car. One more time, no crank, no lights. In all of 45 seconds it deteriorated to nothing.

Now here's the thing. I thought the battery was dead. It's not. Checked the voltages on the battery (trunk) 12v, distributor block in the engine bay 12v, small wire on block 12v, wire w/ right angle attachment on block 12v, wire with straight but bendy (wavy) attachment 0.02v. I checked every fuse in the engine bay as well as in the kick panel. Everything was in perfect condition. Some have suggested a possible short.

I'm basically looking for any additional opinions and tips for troubleshooting. Naturally the wire with no current is also the one that's most difficult to reach and immediately goes into a harness, which in turn goes into the car interior shortly thereafter.

Anyway, I suck with electricity so I would hugely, hugely, hugely appreciate any help that you guys can give me. I know there's some of you out there who know more about electricity than I know about myself, so I hope you'll chime in.

 

well that wire with no current in it, is it suppose to have current or not? whats it for? rather than trying to find a problem, try to eliminate them. thats what i always do with electrical issues. if you suspect its that wire with no current then do everything you can to see its connections. how long has your car not be running? is the alternator ok? just bc theres no voltage doesnt mean that there is a problem. Its just like your brake light wires, you wont see it until you hit the brakes. Lemme know, ive had my head in car wires so much i almost went crazy one night.

 

If you have voltage in the same line at one place, then none further down the path, then most likely you have a dead short. However, if it is a B+ charging wire from a battery, it will either weld itself to the frame at the short, or blow a fuse, or catch on fire. You haven't mentioned a fire, and the battery is indicating good, so most likely is a short somewhere. I know it sucks, but this is the same principle we use on aircraft here in the Air Force. You have to trace the wire back to the short. Look in a schematic if you can and find out where the next junction or connector is. Diconnect it and ohm out the wire with a multimeter. Keep doing this until something reads all crazy. Most wires should read less than 1 ohm if they are good. Let me know if I'm not going in the right direction, or if I missed something...

 

Turboit: 10mos, alternator seems to be ok, but I doubt that would explain the lack of voltage when the car is not started. Correct me if I'm wrong.

Dookie: All signs point to tracing the wire and testing each junction being the best solution. The reason I'm trying to avoid that is because it's a main power wire for the interior/engine, and the loom is huge and difficult to follow.

Is it possible a bad ground could be causin this? I doubt I'd have been able to smell smoke (and I did not) because my exhaust is running half open. All I smelled was hot cat and unburned fuel.

 

Well, I would never rule out a bad ground somewhere. The thing that is important before you go chasing around for a bad ground is to find out if the interior/engine uses a seperate ground than other systems. Check the ground connection going to the tranny or engine block and the one coming off your battery, I think goes to the right. I'm sure you already checked this, but would like to rule it out....

 

eh rather than checking all the ground connections just go to the wire and test for continuity (spelling?) and you will see if its grounded or not.

well one reason i said it might be alternator is because, it may be getting voltage because but it may be on its last leg, you said it cranked, then didnt crank anymore.

i dont see way the main harness would lose voltage unless you missed a ground when you put your engine back together. recheck as many connections as you can, by the book. even check the wiring for your standalone and any gauges you may have.

just for sh#ts did you try to jump it and start it? i duno, sounded like a deaded battery from the start to me and it doesnt hurt to try.

 

^ Ya it sounds like a loose ground wire to me.

 

Yes, I tried to jump it. Then I tested the battery w/ multimeter and it was reading strong throughout hte night as I checked all sorts of connections and fuses and whatnot.

I'm guessing I missed a ground while putting the motor back together. Fortunately I have a good bit of cable lying around. I guess I'm going to go testing tonight and figure out where the problem is. My electrical doesn't look much like stock anymore with the trunk relocation, but it's not too far off either. With any luck I can figure this out within a night or two.

EDIT: BTW, I know how to test for resistance with a multimeter, but how does one test for continuity? If you mean continuity of power, it's dead in that entire wire. The wire from the battery has the 12v and the other two main power supply wires have their 12v. It's the stupid 3rd one that is limp. It has electile disfunction.

 

i'm no genious when it comes to electrical issues (in fact i'm flat out dumb) but it seems to me it still could be the battery. just cause the voltage reads 12v, doesn't mean its pushing enough current.

dead batteries (car or even AAA) still read the correct voltage with a multimeter, but they have no amperage left to get anything done. especiallyl for cars, voltage means crap, its how much current the sucker is pushing that is important. so is it possible your problem still could be the battery?


edit: whoops, too little too late

 

I wouldn’t discount the battery yet! Just because it shows 12V unloaded doesn’t mean it’s O.K. the best way to test the battery is with a hydrometer. If you don’t own one get one! It’s cheap and helps you keep an eye on the state of your battery. The fact you said it “deteriorated” is a clue.
Hang on a minute, what do you mean “I went to run the car for a minute on the way out” and “had my car running last week”? How often do you run your car? Is this clue number two?
Can you get your lights on now (after the car has rested ).
If it is the battery, monitor the battery voltage as you turn on more and more systems. Start with the stereo down low, then crank it up. Then try the lights, next try starting the car.
Sorry but apart from the battery I cant think of one single thing to answer all of the symptoms you describe.

Whoops for me too, beat me to the post. Get a hrdrometer anyway .

 

I'll try jumping it again. I don't get why it'd read 12v everywhere cept where I need it to though.

EXCEED, my car has been down for 10 mos. The battery is a brand new Optima Yellow Top. No, my lights do not go on after it resting. No accessories, no nothing. It's entirely possible it's more than one problem. My car has been wrought with trouble for some time now.

The deterioration thing is what puzzles me most. It started/ran fine last Tuesday, but then degraded quickly on Friday.

 

That is weird how it started fine on Tuesday but wouldn't do anything on Friday. I am taking it you didn't do any electrical type work with it between then and Friday? If not, then I'd have to say starting the car may have shook a ground loose with the engine start. That's the most probable cause. It's most likely a bad connection somewhere. Now the search commences. Good luck!

EDIT: And I feel your pain with the electrical work. Hopefully you aren't color blind like me. That makes it especially fun. Gotta love it.

 

BTW, if you're curious about the **** I've gone through with this whole process:

https://www.evolutionm.net/forums/sh...ad.php?t=83498

 

Didn't so much as touch it in those 3 days, nor did anyone else.

 

Your best bet is to trace that dead wire, as hard as that sounds like it's gonna be, and check every 1/4 inch of it for frays/connectivity in that case. Then check all the grounds front to back ten times over. Hopefully you will find your problem there, if not, it's time to break out the wiring diagram and the highlighter and get to work. Oh the joys. Poor poor Andrew. What have you done to deserve such torture.