Electrical Draining

[PaulTAutoX]

FastCAD, you rock!
OK, here is a thought without having traced things further, could it be that the ignition switch isn't shutting off the systems that have drains? It is a brand new one from Autozone.

Per the fuse box pic he sent, assuming valid for '92:
Fuse 8 - I don't see a trunk light that is active, is there a level switch or something that controls a light there? Chilton's shows a mercury switch.

Fuse 6 - Diagnostic warning lamp, is that active when ignition is off? I do have an airbag light that blinks when the car is running but not when off.

Fuse 11 (largest drain) - radio/ premium sound (I don't have the JBL, was that "premium"?) / power antenna My power antenna doesn't work, but that usually stopped trying after a while I thought. I don't hear it grinding or anything. The drain was present though the radio was off. I suppose I could just yank it out.

Fuse 17 (smallest 40mA drain) - A/C compressor clutch and the blend door actuator, is there a separate clutch "EATC compressor clutch" that operates the EATC somehow?

 

[FastCAD]

Was that fuse panel diagram for a '92 (which is what Paul has)? The layout differs from year to year.

NO "91 (specific)
Sorry I did not catch Paul's '92
Thanks for the correction.
I see, "electrical & audio" gen 1 & 2 forum.

 

[FastCAD]

FastCAD, you rock!
OK, here is a thought without having traced things further, could it be that the ignition isn't shutting off the systems with drain?

Sorry I posted the fuse panel for a '91 specific.
I, would for giggles pull the 'courtesy' bulbs from the trunk, hood & glove box & test the elec. drain again. If you are tesing the fuse with any of the doors open then you are going to get draw on the courtesy light fuse which also carries the clock, radio, keyless entry lamp & power mirrors (15 amp).

 

[BaySHO Performance]

Here's the fuse panel for a 92:

 

[Ta2dResqr]

Fuse 6 - protects the following circuits:
- Instrument Panel Illumination
- Lamp Out Warning Module
- LCD Dimming Relay
- Left Cargo Lamp Assembly
- Left Door Lock Switch
- Left Rear Window Control Switch
- Liftgate Defrost/Wiper/Washer Control
- Liftgate Wiper Motor
- Liftgate Wiper/Washer Control
- Main Light Switch
- Master Window Control Switch
- Police Accessory Relay
- Right Door Lock Switch
- Right Front Window Control Switch
- Right Rear Window Control Switch
- Right Cargo Lamp Assembly
- Speed Control Amplifier
- Warning Chime Module


Fuse 8 - protects the following circuits:
- CD Player
- Digital Clock
- Dome Lamp
- Engine Compartment Lamp
- Glove Box Lamp
- Illuminated Entry Module
- Instrument Panel Dimming Rheostat
- Keyless Entry Module
- Left Front Door Jamb Switch
- Left Rear Door Jamb Switch
- Left Vanity Lamp
- Liftgate Mercury Switch
- Luggage Compartment Lamp
- Map/Dome Lamp
- Power Antenna Module
- Power Mirror Switch
- Radio
- Right Front Door Jamb Switch
- Right Rear Door Jamb Switch
- Right Vanity Lamp


Fuse 11 - protects the following circuits:
- Power Antenna Module
- Premium Sound Amplifier
- Radio
- Redundant Radio Control


Fuse 17 - protects the following circuits:
- A/C-Heater Function Selector Switch
- Blend Door Actuator
- Blower Motor Speed Controller
- Electronic Automatic Temperature Control (EATC) Module
- Heater Function Selector Switch

 

[FastCAD]

I am not the best with a multi-meter but can't you pull a fuse from the panel (one at a time) and then check the battery voltage each time until you find the draw-down? Or maybe at least you can narrow down the problem to a specific circuit. It could be a loose ground.
Just my 2cts. and no more. lol

 

[PaulTAutoX]

I am not the best with a multi-meter but can't you pull a fuse from the panel (one at a time) and then check the battery voltage each time until you find the draw-down? Or maybe at least you can narrow down the problem to a specific circuit. It could be a loose ground.
Just my 2cts. and no more. lol

Maybe I don't understand the response. As noted near the bottom of page 1, I was checking current going through each fuse by looking at the total current coming out of the battery and pulling one at a time. That was how I found three circuits that had too large of a continuous drain. Or is there another way to approach this? Open to suggestions.

 

[FastCAD]

O.k. you have multiple issues confirmed. Most interesting to me is the air bag light.
Check the PCM grounds bolted to the firewall pass. side just to the left of the PCM harness. There should be at least a couple together. If that is o.k. disconnect the PCM
harness (just to the right of the grounds on the firewall) and check your draw down. That may be it. If it is then the PCM is fried.
Imho, you have too many issues at once to just be a coincidence.
Best to ya.

 

[BaySHO Performance]

A parasitic draw can only be checked by measuring amperage. Max draw allowed 50 mA. Checking battery voltage won't work.

 

[PaulTAutoX]

Can someone describe please the location of the PCM ground for me?

Bonus if you have a picture or diagram, but I can follow directions.

I'll go back into the archives here to follow up on the airbag light before I ask questions on that, I think I remember past discussions.

 

[Ta2dResqr]

G101 (SHO): Center of LH front fender apron, near battery

G100 (SHO): Lower LH front of engine

G101 is Body ground, G100 is Engine Ground. Both are for the ECM.

 

[BaySHO Performance]

Paul, these are for a '92. ECU pinouts:



Pins 40 and 60 are the grounds:


C111 and G101 are between the battery and the fender:




I know you live all of 30 more miles from me these days, but I'm still in business if you could do with some help, albeit with the usual backlog.

 

[Bill Strobel]

My 89 has the same problem, I keep a battery tender on it. Have talked to several 89 owners that say the same thing. I need to look at mine again when the weather warms up.