Bill Ball

I went over to help Smurzik with his 90 no start. Turned out he needed a battery. New battery - VROOM!

We decided to look at his car for parasitic draw. So we attached an amp meter across the ground and then disconnected the ground strap. The meter showed 586ma! No lights on (we thought). So, we started pulling fuses. Got to fuse 25, the interior lights, and it dropped 250ma. We tested the door pins and think we found one of them bad. So far so good. Got to fuse 31, power windows, and it dropped to 115ma. After pulling all of the fuses we still have 115ma. So, we have 55-85ma of draw we could not locate.

I recall there is something (alarm?) that is fused outside the panel. If so, where? Are there any unfused circuits. OK, there might be an aftermarket alarm or radio wired unfused for all I know.

Dave A - I think Smurzik needs your help!

Mrmerlin

Hi Bill hey just a thought, look at the ignition relay I think it is # V in fact i would pull all of the relays one at a time and any that have any corrosion on them should be opened even if they look new, plus check under the hood for the pin switch, make shure it is operating, also the hatch latch,ahh almost forgot dont forget to check the connections under the hood at the front right by the cross brace, good luck Stan

the flyin' scotsman

The power window draw maybe from a switch stuck down. Check window, sunroof and rear wiper switches.

The hidden fuses/relays are under the centre console, if you remove it and unplug all the electrical connections perhaps you'll find the 'leak'.

GlenL

The hot from alternator is unswitched. If the diodes are bad it'll drain back through that.

FeedNfrenZ

I had a problem where the the window control module (under drivers seat) wasn't turning off. That module keeps the window circuit energized until you open the door. I did it's function but the module wouldn't TOTALLY turn off. That ended up being fixed by cleaning/chaging the door switches. It's like the door switches supplied enough of a ground to turn off the relays in the module but not a good enough ground to kill the module completely.
The LH and EZK modules are wired directly to battery voltage. Try poping them out and see if the current draw goes to zero.

Garth S

In pulling fuses, did you kill the clock and power bleed for the radio memory? there could be 25 or so milliamps there.

Bill Ball

Excellent stuff. I was hoping it was a stuck window switch too, Malcom. Nope, but Smurz reports his windows behave weird. I didn't quite follow it. Something like you have to hold both switches down to move either window. Needs investigation. That was only 90ma, so he can live with that if he drives the car often or trickle charges it. BUT I don't think he can live w/o the interior lights, a larger draw, as the instruments run through that fuse too.

Thanks for the ideas on the stealth locations for parasitic draw.

I should also say that at one point we did have a reading on only 50ma and I thought we were done after finding the door pin and power sindow draw. But on re-checking it went to 0ver 300 with out. The next time it was 115. It was very confusing. Nothing was active as far as we could see. I wanted to pull ALL the fuses and re-check, but we gave up as it was getting late and I felt we needed Dave A (Sharkskin) who lives nearby.

Would ERRATIC parasitic draw point to anything in particular?

the flyin' scotsman

Bill..........having to press both window switches at once to make them move makes me think of whats common to both.............ground?

Interior lights...........they're all switched off/ or come on when door/tail is opened?

I'd be very tempted to pull the console, lots of electrics under there.

Erraticness points to something barely making good/bad contact...........broken wire/pinched wire/bad ground.

SharkSkin

Looks like a lot of great advice above. Not sure what I could add, except that certain relays "latch" on... you might have been running into this behavior. Pulling the alt wire is a good idea, though maybe not so easy in a carport. When you have all of the relays out, look for any burn marks on the relay sockets. If you see any discoloration on any of the sockets(and even if you don't) there is a possibility that there are some wires melted together on the back of the fuse/relay panel.

I thought sure this was the problem with Ron's car, since he had some wiring that literally went up in smoke... but when we got in there all was well. So that's a roll of the dice IMHO, though *all* of the loose central electric panels I saw at PartsHeaven had melted wires on the backside. I still believe it's more common than most people think.

BTW, On an S4, if you disconnect the B+ terminals at the alternator and still have the current drain, that would point to fan controller since IIRC those run a separate circuit straight off the battery terminal.

On second thought, try this:

1) Disconnect hot wires from top of CE panel -- If drain disappears, back to the drawing board. If not, go to step 2.
2) Disassemble and separate the terminals on the jump post. If the drain disappears, the problem is on one of those circuits, possibly leading to the CE panel; you will have to test them individually till you find it. If it doesn't, go to step 3.
3) Disconnect B+ terminal from alternator, but leave the ring terminals connected to each other. If the drain disappears, it's your alt. If not, go to step 4.
4) Separate the two ring terminals mentioned in step 3. If the drain disappears, it's in the engine harness. If not, go to step 5.
5) At this point, the only thing hooked up should be the fan controllers. Disconnect at the front, and if the drain goes away it's the controller. If not, it's a problem with the main battery cable or the wires to the fan controller.

If the drain disappears at step 1, then you still have a rat's nest to deal with. But if not, the other steps should help you narrow down where exactly the problem is, and keep you from wasting time on the rat's nest if it's not necessary.

HTH

Bill Ball

Yep, perhaps there is a bad ground for the windows.

We had all the lights off. I should clarify the bad pin observation. We documented a door pin fault by watching the red warning lights on the door as we depressed the pins. The pins just break ground when pushed in, right? One of them wouldn't, even with the pin removed. So that means it's not the pin itself, but the harness is grounding somewhere else, right?

I hope we can leave the console alone, but we will pull the side panels and the radio.

Bill Ball

Thanks, Dave. Could help us sort though this for a few hours sometime in the next two weekends? I'm afraid I turn simple electrical problems into Rubic's cubes.

So, the fan controller is unfused. We pulled the fuses to the fans as part of the process and saw no change.

SharkSkin

I'll have to get with the other half & see what's on the calendar for next Sat. -- If I can't do it then it would have to be the following weekend....

the flyin' scotsman

Pulling the side panels will give access to the cables for the window buttons which you can disconnect.

Leave the interior light fuse in place but switch them all off and as Garth suggests pull the radio and clock fuses...........now do you have any draw?

Remember your measuring to ground therefor something is grounding that shouldn't be.

Bill Ball

Dave: I don't think it will take long at least to isolate the defect. Fixing it might be another thing. Hopefully its an accessible component or wire harness segment. If not, we will just leave Smurz with a way to drive the car and he'll have to get it fixed later as he is moving across the country in a couple of weeks. Smurz is in Burlingame.

ew928

Ever resolve the door pin switch?
Don't the window relays stay powered till the door is opened?
I can use power window till door is opened.

And is the rear hatch open during test?
Dumb question but is the rear hatch pin switch taped shut to take that
out of the testing.
Any separate amp for the stereo. My external amp for stereo gets it's own power
from the battery. If I don't pull the fuse the sub with thump when disconnect/
connecting the battery "+".
If you guys are pulling the sidepanel off the center console, might pull the fuse
on the radio. Not sure if the radios are wired to power on without key in.

Ernest (NYC)