Electrical Problem?

[zqaddoc]

Hello All,

My 2002 is in the shop with a nagging problem. If I park the car and try to start it 4 or 5 days later, it won't even turn over. The mechanic has told me when he unplugs the lights that the car starts everyday with no problem. If he tries to find the source of the short, it could be expensive. I just want the problem fixed. Is this electrical? He's saying the car is actually switching back on which drains the battery. What is the proper way to go about fixing this problem.

[Mike Self]

You've got a current draw somewhere in your wiring...if it takes 4-5 days to kill the battery, it's a fairly small one--if your brake lights were stuck on the battery would be discharged almost overnight.

Does the wiring have evidence of being messed with by a PO? Are there places where the original wiring harness has been patched or repaired? Those are always places to suspect problems. Is the radio wired so that it's live all the time?

Are you sure your alternator is charging properly? Is the battery passing a load test? Both can cause a battery to go dead in a relatively short period.

The easiest, but slowest way to find the offending circuit is to remove one fuse at a time and then see if the battery stays up. You'll eventually track down the culprit. I'd start with the fuses that do the lights, and then move on to the fuses that protect circuits that are live only when the ignition is on.

Oh--if you have a 71-73 (not sure about the later cars) and you turn the car off with the turn signal engaged, it will light the right (or left) parking and tail light. This is required for parking on the street in some European countries, and will surely run your battery down over 4-5 days.

Have fun learning...

mike

[TJW]

Here is the easy way for people with basic skills. Remove ignition key.

You can use a volt meter but a test lamp with a small wattage bulb (2/3 watts) is better.

Remove body wire from battery (fully charged) attach test lamp between battery post and body wire terminal.

If you have an alarm/radio/CD player/electric clock, these take power even when the key is off, so disconnect them.

Now is the bulb glowing, if yes, then remove each fuse in turn and check the bulb untill you find the circuit that is affecting the bulb.

4/5 days to flatten a battery is not a short, it is a circuit that is on ie. interior light, or your radio etc.

Make sure you disconnect all permanant powers before checking as said above, if you do not get a glow from the bulb after disconnecting the above then the fault is there.

Try that.