Contour Enthusiasts Group Archives Forums General Troubleshooting Got a battery-eating short--HELP MEEE!!!

Somewhere, under the hood of my car, lurks a predator. It cloaks itself perfectly; and at any given time it srikes without prior warning, leaving me stranded. It is... a battery-eating short! At first, the car behaves OK, sometimes for days at a time, but then it grinds to a halt. The only precursor is the cluster goes crazy: the tach swings around like mad before shutting down, the temp guage just plain quits working, and the other lights light up like it's Christmas... when there's no reason for them to. And when the battery gets too low to turn the engine, the wipers turn on for no good reason.

I've eliminated the alternator as a culprit: it's putting out the proper charge. A bad battery alone shouldn't do this, certainly not running down while driving. And I can't figure out what kind of component could still stay on that would draw 3-5 amps (the amount the charger still keeps dumping in, continuously, while the battery's still hooked up). However, the insulation on the positive cable and all the auxiliary wires coming from the same clamp is just... gone. All the insulation crumbled last year when I replaced the alternator. I'm thinking Occam's Razor here: bad and exposed wiring equals short at the source. My grandfather thinks it's in the dash or the column, since things go haywire when the power goes down. I'm wondering what you think, especially those of you who've survived the same or similar problems.

BTW: I took a circuit tester to the disconnected positive clamp, touched the probe to the positive post, and the light in the tester briefly lit up. This was something a Ford technician told me to do to check for the presense of shorts. Does this sound familiar?

Okay..

some things I need to VERIFY, first:


1. HOW do you know the alternator is good? (you mentioned the "correct charge" but nothing of how you obtained it, and if you tested through a load, or at idle, etc)

2. the short is not any more likely to be in the gauges than the battery, simply because of the finnicky needles, and wipers. that is simply an effect you receive when the voltage is at an extreme low. That would happen if the problem was not in the gauge area, as well.

3. You placed a test light across the open created when you removed the postive cable. (from the positive cable, TO the positive terminal of the battery. in essence connecting them back together, through the test light. The light illuminated because you had voltage running through it.. not because of the presence of a short, etc...


I would do the following:

VERIFY alternator and battery condition/operation (perhaps at a parts store, where they can test under a load, etc) and make sure they test under a load, and not just at idle.

While running: 14-14.7 volts across the battery terminals.. same at load, shouldn't drop at all.

While off, and with surface charge removed (all interiors and headlights on for 60 seconds) the battery should read 12.0 or higher.

if its lower than 12.. bad battery. (or PERHAPS a SERIOUS draw, but that would likely cause an off charging voltage, too)

if the charging voltage is low, then look in to those reasons (poor connections between the alternator and battery, etc)


Ray

I am an ase certified tech, elec is my main thing. Sounds to me like the battery voltage is just getting too low and the car is dying... like when your alternator quits chaging. If you had a short at the alternator charge wire to ground, the main 175 amp fuse would blow, or there would be smoke and fire. if you had any kind of short at the battery, you would see smoke and there would be fire.... if there was a short in the column fuses would blow, or there would be smoke and fire... see a pattern develope? Short = blown fuses or smoke and fire... no blown fuses or smoke and fire = no short.

If you had a constant drain the car would be dead if it sat for a day or 2.

If its not just a bad alternator (which I think it is) I am willing to bet you have bad connections from all your crappy cables... bad connections = heat, and when heat goes up, resistance goes up, and that means all the energy is used to make the heat at the bad connections instead of power the car.
I would almost garuntee if you replace the batery cables and the main charge wire from the alternator to the underhood fuse block your problem will be fixed.

Oh yeah, also check all the grounds!!! a bad body ground will also cause all your woes you describe.

The alternator is still one of your biggest suspects. Sometimes the diodes fail in such a way that it causes an intermitant short. When it does short, it is usually a very big one. There is little else that can cause a large intermitant short.

I hate to tell you, but it sounds like your alternator. I replaced four batteries in my 99 Suburban before I took the alternator off and had them do a proper bench test on it!! And guess what, it was bad all the way around!!

Oh, and about testing for the shorts? I was told the same thing, and then I did that on my 2003 Ford Ranger, I did that on the neighbors 1999 Chevrolet Suburban, and on the 1999 Contour, they all lit up, as though they had a short. After talking to more people, the explained that there is a lot more to checking for a short!!

I'd have the alternator properly tested. It killed three batteries in one year for me!!

I had same problem as you all lights flicker and gauges went wild .i read what every body told you sounds correct same as my machanic told me we tested at the shop and my alternator was fried changed it and now it works fine

April wrote: "However, the insulation on the positive cable and all the auxiliary wires coming from the same clamp is just... gone. All the insulation crumbled last year when I replaced the alternator"

You may have the famous lousy wiring insulation problem. The insulation may well be missing elsewhere in the engine compartment too. Check out recall 99M03 - 99M03 recall. It says it only covers through model year 97, but it sounds like you have the same problem.

I had the same symptoms in my car a few years ago - dead battery after a few days, crazy instrument panel and wipers. The dealership disconnected the trunk and hood lamps and the problem went away (they were blaming my sony stereo as well).

Not an elegant solution, but no more dead batteries. Then the A/C stopped working on the car this summer, and once I saw all of the bare wiring, I was amazed the thing hadn't burned to the ground. It is getting the recall.

Good luck!

Jeff