'82 300D Turbo electrical problem
 

I don't know what it is but my battery keeps going dead over night. It is brand new, just bought it. I can jump it with my Jeep no problem and it runs and starts fine until it sets for like 10+ hours. I checked and made sure all the light are off, antenna down, doors shut etc. Any idea as to what the fudge is going on? I sure don't wanna have to take it to a mechanic as money is too tight for me to do that for a while.

sometimes the glow plug relay gets "stuck" causing your battery to drain down. Pretty easy to test, lots of info here by searching.

Until you find your short, pull the positive battery cable off when you park it.
It'll keep your battery happier, your Jeep's alternator happier, and take less time when you go to start it.

Oh yeah, if you don't have a meter, now's the time to buy one. Shouldn't cost you as much as an hour at the shop, and will pay for itself many times over. My personal favorite is Fluke. Probably find one on Ebay for $50

Harbor Freight had Digital Volt/Ohm Meters from $3-$9; well worth the money. Regular Auto Part chain stors have them at twice the amount. Only buy a digital one the the older inexpensive analog ones are hard to see and if you revers the polarity it will sometime damage them.

Also found at Harbor Freight of one of the Auto Part chains stores is this battery shutoff switch that I had on my Volvo (intermittant short circuit).

You need to buy a digital voltmeter. As others stated, very cheap at Harbor Freight etc.


***First, to test your glow plug relay. Turn car on to glow as normal. Make sure after exactly 30 seconds (you can count using the clock, if it works), you hear the 'clunk' off your relay releasing. You can cross check this by looking at your dome light - it will visibly brighten when the glow plug relay releases. This is important to do first - if it is stuck, it will blow the fuse in your brand new meter since the glow plugs consume more than 10 amps, the max on most meters.

Okay, after you've done that:

- Test with the car off, key out of ignition.
- Remove negative battery cable from battery
- attach multimeter in series with negative battery cable, with meter set to measure 'current'.
- 4-5 ma is the amount I measure on my 300D with everything off
- note the current consumed. I had the same issue, and a current drain of 30mA was what I measured - enough to kill it overnight. In my case, it was traced to two of the cluster connections being mixed up by PO.
- pull one fuse at a time until you note when the current drops way down
- that will narrow it down to a system or two, look at the fuse map



Good luck :-) Let us know what fuse is causing you trouble...

dd

Thank y'all very much.