Black 84 Z

I have an 84 Z28 that I am unfortunately not able to drive as much as I'd like so it will sit several days at a time. Occasionally the battery will be dead when I go to start her up. I always just chalked it up to lack of use and the Florida heat. Since I've had a bit more time lately I wanted to get that straightened up so I took the battery to get tested and it was no surprise bad. New battery installed and she starts fine, until day 3. Try to start it and dead, like really dead. So I know something is draining it. Get out the multimeter and it only shows it draining 20 MA so now I'm confused. Take the car for a short drive and come back and test it again. Now it says 98 MA and I'm really confused. Unplug a few things under hood and nothing changes so I leave the neg cable undone and call it a night. Next day after starting it and warming it up I try again and back to 20 mA. WTH? On a whim I test the alt diodes. Put the voltmeter on the battery posts and it reads voltage which I deem to mean a bad diode. Turn off the car, unhook alt and use diode test on multimeter and appears OK. Now I'm totally stumped. Can a diode only work or fail intermittently? That's the only thing I can point to that makes any sense to my novice self. What do you guys think?

jharrison5

Had a similar issue on my "88 GTA and it ended up being a bad door switch on the passenger side.

Black 84 Z

Yeah, I'm just baffled at how it could be so hit or miss on the readings. Not a little variance but totally different readings.

Black 84 Z

OK, had the alt tested and everything passed at 2 different parts stores (didn't trust the first guys abilities lol). Brought it home and tested the draw again and back to 19 mA. I guess next step is to keep testing it until it reads a higher draw and then start pulling fuses until it drops down again. Thoughts?

Black 84 Z

Update
Finally was able to get a bit of help so I could test each fuse and see where the drain is coming from. After testing each it looks like the trouble spots are the ctsy fuse and the hazard stop fuse. Looking up the ctsy fuse on my car it should include the interior lights, door locks, and hatch release. To test each of these should I test the Amp draw in series or test the volts in parallel? If it's in series then testing the hazard and stop lights should be easy by just removing a bulb and touching each lead to complete the circuit. Parallel might be tougher. Which one should I use?

Black 84 Z

Since I wasn't sure what to do I pulled each bulb in the rear and tested each socket with the ammeter. None of the registered anything. Is there something else hooked up to the stop hazard fuse I can check.
Also, the sockets all had some off white pasty gunk in them, do they need to be replaced? I looked up and found the individual sockets but can't find a complete harness if I need to replace them all.

dagwood

iTrader: (5)

Does your hatch have the automatic pull down? If the motor isn't going all the way down it will create a drain. You will hear it click when it hits the switch when it's all the way down. Either move your hatch bumpers in, or raise the latch mechanism a little bit if that's what's going on.

Black 84 Z

Nope, no pull down motor luckily. When I get the chance I will disconnect the entire light harness and see if the drain is before or after it. I believe it is the connection behind the pocket on the driver's side. We will see if that can narrow it down.