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1995 Grand Marquis LS excessive current draw

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  #1  
Old 08-04-2023, 01:37 PM
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Default 1995 Grand Marquis LS excessive current draw

The battery goes dead after a day.
The circuitry on the #8 fuse draws 350ma with everything off.
All interior, hood and trunk lamps verified off.
The problem is something else attached to this circuit.

Any ideas as what might be causing this?
Anybody have a wiring diagram of the circuitry on the #8 fuse?


 
  #2  
Old 08-08-2023, 01:56 PM
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Any after market stuff like an alarm system, or speakers or amplifier? Anything that looks like a hack job under the dash or engine bay? Do you have a tracking device on the car?
 
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Old 08-08-2023, 03:09 PM
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Thanks for the reply.
No. I recently inherited this from my mother. It is totally stock and looks like it just rolled out of the showroom. Only has 80k on it.
I did all the repairs. So nobody had a chance to mess things up.
Problem started a couple of weeks ago so I tested charging system and replaced the battery.
When the problem remained I checked for current drain. I'm just leaving the fuse out for now. Temporary cure.

Lol. I can't imagine anybody wanting to put a tracker on me, If they did it would make more sense to tag my other car.
 
  #4  
Old 08-08-2023, 04:34 PM
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Most owners' manuals have a diagram of which fuse provides power to what, Most public libraries have repair manuals online . A subscription to All Data would have the schematics.
 
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Old 08-08-2023, 05:24 PM
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Looked it up. 1995-1997: Lighting Control Module, Power Mirrors, Remote Keyless Entry, Clock Memory, Radio Memory, Electronic Automatic Temperature Control (EATC), Power Door Locks, Power Seats, Power Windows, Police Spot Lamps. 15 amp fuse.

One at a time and check the draw with a volt ohm meter. I would try disconnection of driver door connection at door jamb harness. That would include door locks and windows and mirrors. and keyless entry Disconnect power seats at harness under the seats left and then right. That would take out the seats. You obviously don't have a search light. The EATC is the most expensive thing. By process of elimination, show me what works and it will show you what is wrong.
 
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Old 08-09-2023, 09:04 PM
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Originally Posted by flackbait
Looked it up. 1995-1997: Lighting Control Module, Power Mirrors, Remote Keyless Entry, Clock Memory, Radio Memory, Electronic Automatic Temperature Control (EATC), Power Door Locks, Power Seats, Power Windows, Police Spot Lamps. 15 amp fuse.
Thanks for the reply.
I have a list similar to yours in the owners manual.
Neither list is accurate in the fact that with the fuse removed all the listed stuff works.
Only the lighting, radio and clock are disabled (that I can find so far).

I'll pull the clock and radio, which are not hard to get to. and see if they are the culprit.

If not I guess I'll have to renew my Alldata subscription for the schematic.

PS: I posted this response earlier but it never showed up for some reason.
 

Last edited by LostTwo; 08-09-2023 at 09:15 PM.
  #7  
Old 08-09-2023, 09:53 PM
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Well, it looks like Ford speaks with forked tongue. Wiring changes happen on the production line and the documentation doesn't always get updated. In the previous years, #8 supplied power only to the cigar lighter.
 
  #8  
Old 08-29-2023, 05:24 PM
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Finally got a chance to work on this.
Problem was the radio. Specifically a transistor in the tape module.

I could fix the tape module, but I don't use tape. If I get ambitious I'll install a Bluetooth module in its place.
For now I'll just leave it out. Radio works otherwise.
 
  #9  
Old 08-30-2023, 02:45 PM
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How did you track it down to a bad transistor? Was the tape motor running all the time? Who plays tape anymore anyway? That is soooo 80s. Today's radios are much better and swapping one out is a walk in the park. Glad you found it.
 
  #10  
Old 08-30-2023, 06:00 PM
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Way many years ago I made a living repairing electronics. For me fairly trivial to track down.
 
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