So I've been fighting a parasitic drain since I bought the car(1981 B210.) I can't seem to find any evidence of a drain other then a dead battery in the morning. I've pulled all the fuses, disconnected all the lights, and I'm still getting a slight drain. Just enough to kill the battery by morning. Theres no evidence of any wires grounding, and I've gone over just about everything with a meter and found nothing. Any suggestions?

Have you checked the battery completely isolated, they self discharge when they're worn out, the sulfate separates and shorts the plates or something like that. Try disconnecting it, charging it and leaving it over night, then check the voltage.

Yeah, thats been done multiple times. The battery is fine as long as its left unhooked when the car isn't being run.

Here's how to find the problem.

Turn off the kar
Remove the negative battery cable.
Take you ammeter and connect it to the NEG battery post and to the NEG battery cable
Note how may milliamps are being used.
Pull a fuse
Check the ammeter
Pull another fuse
Check the ammeter

When it stop showing current, it is something on that fuse circuit.

new battery? fly me over and i will have a lool

seeing as u have had it for a while, is it only every now and then? surely u havent stored the car for 20 odd years?

could be a faulty diode in the alternator or reg
try disconnecting it, then see if that helps

Thanks for the recommendations. I'll go check now and get back to you all.

ddgonzal- Checked it. I still had a drain after removing all fuses

bailz- I just bought the car about 2 weeks ago. I'm the third owner. The original owner drove it until it stopped running. The guy I got it from only had it a few months. Put some new parts in in and $550 later, shes mine.

tommo- your the winner! that was the drain. However, I didn't disconnect the positive or negative cable. I unplugged the plug on the back above the ground.

Anyone know what it's for? It's causing a pretty substantial drain. I'm not an alternator, guy so I'm not sure if this is a stupid question.

How many milliamps current did it draw? Alternator will draw some by design but not enough to drain your battery for many days.

That plug is for the alternator Signal and Lamp wire (LS). But both are fused, so if you pull the lamp fuse and the alternator fuse it shouldn't occur.

Tommmo was refering the big red/white wire on the altnernator which is unfused, and it a diode protected form draining your battery.

Replace the alternator to test. I have one you can borrow, i'm in the Eastgate area.

With the harness connected it draws .88 miliamps. Disconnecting the alternator wire doesn't help solving the drain issue. The alternator started making a bit of noise because it seems as if a bearing is going out so I just may replace it anyways. I appreciate th offer though.