I bought my 1991 Bertone Coupe last month (http://www.national-auto-sales.com/vehicles/011447.jpg) and was really upset that such a nice car like this would have such a flaw as the one I discovered the following morning when I wanted to start the car. I didn,t think nothing of it until I read thru the Brickboard and realized how common of a problem this really was. So I decided that if i'm going to keep this car, this problem has to be corrected. I'm going to take this project upon myself and hopefully come up with a solution, (for my sake)and for all you folk's in despair (current 780 owners).

Here is the first of many updates. Those of you current 780 owners know all about the electrical drain problem these cars have. Currently my car has a current draw which fluctuates depending on ambient temperature between 24 and 29 Milliamps. I pulled all the fuses that were showing some kind of draw until I was showing zero on my meter, and started one by one to record how much of a draw each individual fuse had.

Here are my results along with my eventual course of action.
(if any of you have some input, please don't hesitate)

Fuse# Amperage draw
#1 Fuel Pump(eng control) 5.78ma

#2 Headlamp flasher 2.52ma
Central Locking
Hazard

#5 Central Door Locking 12.60-17.00ma (fluctuates)
Glove Box Lamp
Clock
Radio
Pwr Ant.
Central Roof Courtesy Lamp
Luggage Comp Lamp
Engine Bay Lamp
Floor Courtesy Lamp
Warning Lamp Doors
Sunvisor Lamps

#6 Heater Fan .82ma

#23 Rear Amp .18ma then drops to zero

#24 Pass pwr seat 1.08ma
#26 Driver pwr seat 1.16ma


Everybody reports aprox 24ma draw. In my case you can see were the 24-29ma fluctuation is coming from. Although fuse #5 seems as the obvious culprit, I don't think it's the only one at fault.

Fuse #2 and #5 have the central locking mechanism in common. Other items on #2 fuse are unlikely to be faulty. Will check central locking mechanism first. Also central locking mechanism (switches ect.) are exposed on the backside to atmospheric temperature. The CLM is the one item all the other models do not have which might explain why the 780 is the model with this electrical problem. If CLM is ok, will continue down #5 fuse list.

Fuse #1- I know the computer has to draw power to retain memory. Will check my 1991 940T to see if 5.78ma is normal.

Fuse #24 & 26 Should have no power drain what so ever. Will check power control switch clusters after above two.

Fuse#6 Will verify and compare with my 1991 940T. May just be the temp control unit. Still there should be no draw.

As for fuse#23 rear amp. There is something very funky going on there. There should be no draw there. But I have a feeling that there is an intermittent thing going on. I will leave this one for last.

If any of you guys (780 owners) wish to tackle this project along with me, basically your just inserting the fuse for that particular circuit. All the other fuses remain out. (the ones you already ID as having a draw)Then you start isolating the circuits by pulling the plugs on the components within that circuit as your taking a reading. If you see the amperage draw drop then you've found your culprit. Clean the plug and component end with electric contact cleaner, plug it back and see if it made a difference. If not, then the problem is internal. Open up the component (if possible) and check for defects, also clean with contact cleaner. Plug it back and hope for the best. If not, then replace.



Thats it for now. Check back next time.

Regards,
Julio