Dano
I installed a battery in my 1984 S to check a few of the electonic systems. The PO said he always had a dead battery; another reason for him to discard the car. I noticed NO interior overhead light bulbs. I installed the upper front bulb and it does not fire. Then turned the key to run. The $ .50 toggle switches from the "switch tower" all worked; windows, roof, rear wiper. Headlamps lit and raised. The fuel pump charged, marker/turn/four ways work. I turned the key off. somethinhg near the rear wiper was still running/humming. I am suspecting the rear hatch release. Rear hactch will not latch upon closing. I disconnected then reconnected battery and it stopped.
Dano what do you mean "checking the jumper"?
What is a "jumper circuit"?
Why do you remove the interior light fuse? ... other than disable the light and going to dead battery. (I see you refer to rebulbing and maybe grounding out the fixture. Correct?)
Is there no other way to fix the problem?
You mention the clipboard and system check. If something is not working wouldn't I know it's not working?
What would I be looking for?
In 944's, I pulled the fuses one at a time (there are many) with an mili amp meter accross the negative battery strap until the meter was zero.
Once you discovered the antenna, hatch release and int. light "leak", how did you make repairs? THX G-Man
Quote:
Originally Posted by 924CarreraGTP
MPDano said I should post this to this thread, So here it is.
Porsche 928 electrical short tip!
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Many times the overhead interior light can short and drain your battery. You can spend years checking the jumper, cleaning the grounds and pin connectors and never find it.
It is a common problem and you must remove the fuse to the overhead light.
Another thing, doing a draw test and pulling every fuse to find a short is tedious while standing on your head in the 928 floorboard. You are better off getting a clipboard, checking all systems and writing down the ones that don't work. Remove one fuse each day from the nonworking systems until you find the short. I narrowed mine down to the trunk latch, antenna and the interior light. The interior light was the short.
I hope this helps with your Shark ownership.
If you talk to enough people somebody will eventually tell you that the overhead lights short onto the body when the fixtures are rebulbed or due to the tabs bending. Its a common problem but so many people will tell you to check your jumper circuit and grounds only to leave you in the same place. My 928S now holds its battery charge for months on end.
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