Fuse num 4: autoradio or not ?
 

Hi everyone,
I installed yesterday an original Bremen SQR46 on my ‘86 930. I found all the required wires, stayed hidden for years.
Everything went fine : black for ground, red for permanent +, and finally yellow for non-permanent + (ie current only with key in).
Great sound and happy that it went so well.
But … I then realized that the clock had stopped. So I checked the fuse panel and saw that the fuse number 4 was smashed (allocated to internal lighting, clock and radioI). So I put new one, but it smashed also under my eyes!
Weird is, that the autoradio could play with a dead fuse !? But all internal lights were down (and the clock).
Any clue ?

You could test the current load across it and compare it to the fuse - that will help you. If it is marginally over loaded maybe go up a size. If it is grossly overloaded, wiring fault.
It is supposed to support Clock/radio/interior lights and AFR gauge (?) according to my diag. 5A.
Alan

Alan, ok thanks.
Do you mean wiring fault which would be car related or radio related ?

You can put an ammeter over the fuse unit. Check the load.
Then individually pull wires from the fuse unit and see where the critical load is.
Alan

Ok thanks. Will do 😉