lostinatl

My lights on the interior work only for a short time before blowing the fuse, over and over again.

What is on that circuit....two lights on the top one on the glove box.....(I am assuming at this point). Is it just those three, or only the two on the roof line? I need help so I can try and trouble shoot.

What about the trunk, engine light are they on the circuit?

Thanks
Vince

creaturecat

trunk and engine light are on the same curcuit

lostinatl

The clock also?

Porschenut_Lee

Has anyone found a solution to the problem stated above? I have seen a few issues almost identical to this in the archives, but have not seen anyone reply with a solution. Does anyone know what might be causing this problem? My car is an '84 911 Targa with 93,000 miles. Fuse takes a couple minutes to blow, but this is about as long as it lasts. Original fuse was a 5A, have been replacing with an 8A due to lack of availability of the 5A fuses, and the 8A is still blowing.

Additionally I have had a very slow drain on the battery, several days of sitting and the battery is dead. Don't know if these issues could be related.

Where do I start? Thanks for the help!

old man neri

If you take out all the bulbs does the problem still exist?

Porschenut_Lee

Old Man Neri,

That would be a good place to start.........My trouble shooting skills shut down when it comes to electrical issues. I was born and bred a mechanical guy. Thanks for the thought!

old man neri

To me it sounds like you have a bit of a short.. Time to bust out the Bentley, look at the circuit diagrams and see what feeds off of that one fuse. Try to isolate each path. Hopefully you will find it. Problems like this are a PITA.

scarceller

Disconnect the engine compartment light. This housing gets old quick because of the environment. Take a good look at the housing and also see if the light even works. This is the most likely bulb and housing to cause issues if it gets rusty/old.

If you have an AMP meter put it in-line after the fuse to see what/how much current you are drawing then start unpluging components like the front trunk light, rear engine light, clock, interior lights ... you'll find it quickly this way.

84_Carrera

Look at the door-open wiring switches too - mine doesn't work at all on the pass. side to trip the light, but the driver's works still.

gerrygug

I also have an 84. My interior lights did not work at all. Traced the problem to the after market alarm system that was cut into that circuit, utilizing the door activated switches as alarm points. If you have an alarm, check to see how it is wired. The wire color to the lights is brown.

Porschenut_Lee

Thanks for the input guys, I will post my findings when I get a chance to start poking around.

Dan Cobb

Please don't forget that little light in the dash just above the glovebox! It has a switch inside the glovebox door to activate the light IF the 3 position switch AT the lens is in the correct position.
I forget the orientation, but the 3 positions are:
1- on
2- off
3- Glovebox activated
+++

gerrygug

Dan,
Does that switch have any effect on the operation of the interior cabin lights?

Edgy01

Keep in mind that these cars are putting on some years. Corrosion on electrical connections is adding some resistance to them. Everyone with an 80s era 911 need to pull all their fuses out periodically and clean up their contacts,--the holders, as well as the ends of the fuses, themselves.

jester911

It really is a good idea to have a decent wiring schematic to help troubleshoot these problems. The Bentley manual is a must in my garage. I had a problem with my windows blowing fuses and finally I looked in the manual and found the power seat was on the same circuit. That wire was pinched under the seat. It would have been a long time finding that without the diagram.