Alright fellas im having a hard time with battery drain. Ive found a wire that has power to it with the car off. It doesnt seem to be fused to anything i know because i removed all the fuses to try and track my problem with no luck. Alternator isn't plugged up as well. Anyone out there can identify this harness? Any help would be perfect. I cant find this one on Google. I don't know if this is true but someone said that it was the under hood light and that it supposed to be on constant.

 

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Looks like the battery feed to the blower motor high-speed relay.

 

From the starter there are a number of fusible links. One of these links provides power to the blower high speed AND the underhood light. The connector for the underhood light is screwed to the firewall just above the blower. From there, there should be an inline fuse and then the light which operates via a mercury switch. Hood open, light on. Hood closed, light off. If the light has been removed, the connector will still have 12 volt power but there will be no current flow.

 

So removing the fusible link and disconnecting the connector will fix the problem. Sorry kind of a real rookie with these things. Where is the relay located?

 

AC or non-AC equipped originally? I have electrical drawings for both and will post them later this evening. You should be able to figure it out from there.

 

Yes it had ac but PO replaced the engine without ac. Thanks

 

The harness' are different between the two and so is the wiring for the underhood light (as far as I know). I'll check when I'm back at my PC rather than my phone.

 

Doesn't look like the underhood light.

Looks like the battery feed to the blower motor high-speed relay.

If you suspect your underhood light is draining your batt, take out the bulb. One of 2 things will happen.

Nothing (drain continues): your drain is elsewhere

Fixes it (drain is cured): the UH light is doing what everybody else's does too. Meaning, in addition to being merely USELESS, it's actually NEGATIVELY USEFUL aka harmful. Leave the bulb out.

 

No i didnt think it was the under hood light someone else said that lol never had a bulb or assembly.

 

What steps have you taken to verify you actually have an abnormal drain vs a weak battery?

The connector on the firewall is for the HVAC system. It just happens that the hood light on some thirdgens taps into power there. Some later cars have a smaller plug off the main ECM harness instead.

With a good wiring diagram, a digital volt/ohm meter, and some time and careful effort, you should be able to isolate which circuit in the car is causing the drain. Assuming of course that it's not a weak battery...

 

Precisely.

Meanwhile, the plug in the pic, looks like the battery feed to the blower motor high-speed relay. Not likely to be related in any manner way shape form or fashion to a battery drain.

 

Well ive dont the parasitic amp draw test it came out to be 4.00 draw. I first started to remove each fuse one by one with the CTSY WDO fuse drawing to 3.86. After that i went ahead and removed all fuses and disconnected just about every accessory i can find from pwr seat, Window switches, door locks, radio, etc.

I later found out that my alternator was wired wrong. Ive replaced 2 batteries and alternator and starter. Since then ive used my light prob tester to come to find the wires in the photos about have has power to them. That is with the car in off position. Im betting that im missing something very small in this puzzle.

 

Have you located the accessory fuse block behind the drivers side kick panel? Or the convenience centre that holds the flashers and warming buzzers?

 

Yes ive found the flasher panel. Ive replaced the signal flasher before thats the only thing ive done with flashers

 

There may also be a second fuse block as I mentioned. In my 86, it's located behind he drivers side kick panel. Since my car is thinly optioned, IIRC there was only one circuit connected to it. In more heavily optioned vehicles, I understand that it can get quite busy.

Not that you need it at this point, but I've attached the schematics I had mentioned. One specifically shows the under hood light connected directly to battery power via a fusible link.

One other thing that relates to an experience I went through with a battery drain situation and that's to do with the alternator. Quite by accident, when searching as you are for the culprit, I rested my hand on the alternator and it was very warm to the touch. This was despite having not been run since the previous day. As it turns out, as it was explained to me, the diode pack in the alternator had developed a short and was pulling power from the battery. Replaced the alternator and no more trouble.


Heater schematic non AC.


Heater schematic AC equipped.

 

Thanks for the diagram. It got dark pretty fast here so I'll look for the secondary fuse block and see what it comes out to be. I really appreciate your help everyone

 

There are several circuits powered directly off the battery that don't go through the fuse block. Follow the positive battery cable, it'll go to the starter, along the way it might lead to a junction block. You'll find fusible links at the positive terminal of the starter, and if there's a junction block you'll find more there.

The wiring diagrams in the service manual will show you what is powered off each fusible link. They'll be in the pages labeled "power distribution".

 

 

I'd suspect an amp.

 

Any luck?

 

No luck as of today. I'll try my best at tracking this.

 

It was suggested that maybe some added accessory (post #20) might be the cause. Does this vehicle have an aftermarket stereo and amplifier? (although I suspect if it did that would be one of the first things you would eliminate).

 

Yeah ive unplugged everything to my knowledge. Never had a sound system. The radio that i had i unplugged.