Battery drain on 85 GT??

[Donster]

Anybody know of things that can drain a battery on an 85 GT overnight? Has happened two nights in a row now!

Rear lid was closed, no lights on, nothing obvious. Only recent changes were a new MAP sensor, which I doubt would have an affect on the electrical system.

Any gremlins I should know of?

\D

[TopNotch]

Feel of both of your headlight motors. If either one feels warm, or feels like it's vibrating, that's the culprit. Disconnect it (blue wire, I think).
The old-style headlight motors have an internal limit switch that's supposed to turn the motor off when the headlights are fully closed or open. That can fail, leaving the motor on.

[Donster]

Nice - thnx Pat

\D

[Tha Driver]

A lot of times the trunk light will stay on. The way to find out what it is, is to disconnect one terminal on the battery. Use a 12 volt light hooked up to the battery & the cable end. If there's a drain, the light will light up. Pull each fuse until it goes out & you have the circuit the drain is on.
~ Paul
aka "Tha Driver"

Custom Fiberglass Parts

[Fierofool]

I had that problem with it while I owned it.  The right headlight motor actually melted into one piece.  I rebuilt one and replaced it.  You may be starting to have a problem with the left one.  When the headlights are retracted, watch to see if the knob on top twitches.  You may even hear the limit switch or relay tick.  If so, that's the problem.  I don't believe I rebuilt the left one.  If the motor halves are bolted together with screws, then it's been rebuilt.  I have enough parts to rebuild it, if needed. 

[Donster]

As so many times before, Charlie was dead-on after I told him it's the fuel pump that won't stop running.
Oil Pressure Sending Unit is bad
Replacing it tomorrow morning.

BTW: YOU ROCK!

Thanks for the pic

\D

[jwrape]

I find it really crazy how Pontiac (GM) made these headlight motors so sensative and troublesome.
I am in the process of rebuilding mine. I hope this corrects them for many years to come.

[TopNotch]

The best solution for troublesome headlight motors is to upgrade to the 87-88 system. Some do it by changing out the whole headlight wiring harness, but you don't have to do that. You can splice the controller into your existing harness -- the color codes are the same. You just have to remove the old relays, and, of course, change the motors. On my 86 SE, I put the controller under the brake master cylinder. It's spliced into the original harness, and the motor wires from it go directly to the new motors. The old motor wires are still in place, and the old motor connectors are just dangling. I could, if I wanted to for some strange reason, go back to the old system by putting back the old motors and relays and connecting everything up.

[Fierofool]

And on the other side of the coin, I have a set of Generation 1 motors that had been rewired with Generation 2 connectors and installed in an 88. 

If anyone is interested in totally eliminating their headlight motor problems for the life of the Fiero, I may have a solution for you very soon.  I may remove the flush mounts from the yellow 86SE and put them up for bids. 

[Donster]

flush mounts?
Heck yeah! I want them 4 the 84!

[TopNotch]

And on the other side of the coin, I have a set of Generation 1 motors that had been rewired with Generation 2 connectors and installed in an 88. 

Did you take out the limit switches? If not, the limit switches may disconnect the motors before the current builds up enough for the controller to disconnect them. That means that the controller would remain energized all the time. It wouldn't draw very much current, so you might not notice it, but it could have a detrimental effect on the controller over time.

[jwrape]

flush mounts?
Heck yeah! I want them 4 the 84!

I am planning on doing mine low profile.
http://www.fiero.nl/forum/Forum1/HTML/076247.html

[Fierofool]

The ones I have are quad lights, flush mount with clear covers that fit into the recess where the original retracted doors fit. 

TopNotch, I asked Kevin to pick up a set of motors at pullapart if he found any.  Those were what he brought me, so I don't know what they did with the vehicle wiring.  The limit switches are still in these motors and all 3 wires are connected to the harness.  I haven't looked inside to see if there are any modifications to the limit switches. 

The blue and gray wires from the motor have been spliced together and attached to the green of the 88 connector.  The green from the motor is attached to the gray of the connector.  The motor case hasn't been opened, so they didn't remove the 2 dogs on the motor shaft that control the limit switch. 

[Donster]

Ok, no more battery drain, as the pump stops pumping now when I turn off the ignition

Only drawback was I had to take out the battery to get to the OPSU, but once I had better access, it was a snap!

Thanks for the picture Charlie, made it much easier.

To make up for lost time, took her for about an hour spin last night with my father who is visiting and put about 50 miles on her. Running good, except for the occaisional belt squeal

\D

[Donster]

Additional info about Oil Pressure Sending Units:

When I unpacked the new one and shook it, it rattled on the inside, which is normal. I shook the old one and it was solid, nothing rattled, which indicates it's stuck or clogged. I dropped it by mistake, picked it up and shook it; guess what - started rattling on the inside again.
I intalled it, just to humor myself and it functioned as it should! Funny, eh?
 
Didn't want to take a chance though and put the new one in again, as I don't trust them once they've failed, better safe than sorry.

So if you ever have a fuel pump that won't stop running, even when the car is off, check the OPSU, take it out, knock it around a bit and see if it starts rattling again on the inside, as it should. If nothing rattles insite it, it's baddly clogged or just defect. You might be able to get another few miles out of it until it really needs replacing.

\D