Electrical questions regarding radio fuses

[pablo94sc]

Hey everyone, I'm looking for a quick clarification on the fuses used for the radio in an '89 MKIII (automatic) with a 7M-GE engine. Between an my Haynes manual (no specific wiring diagrams for 87-89 models) and an electrical diagram for a '90 model I found online, I'm at a bit of a loss.

Anyway, according to the Haynes manual I have, the '89 only has a 7.5A fuse for the radio while the previous years had both a 7.5A fuse and either a 15A or 20A fuse in the junction & fuse boxes (DS kick panel). Does the DOME fuse (20A) tie into the harness for the radio as well (seems to be in the same location as the previous years RADIO2 fuse)?

Reason I'm asking is there is a ground short somewhere in this car that is causing the speakers to crackle intermittently, and continues to do so after pulling the 7.5A radio fuse. This also failed to activate the anti-theft code in the radio, so makes me pretty sure there's another circuit I'm missing.

One more question... the wiring diagram I have for the '90 appear to show a common ground setup for the car, but the speaker wiring seems wrong. This car has the 6 speaker setup, but no rear sub(s) as the wiring diagram implies. What am I missing here?

Thanks for the help.

Paul

PS: Car has been in the family since new. I'm inheriting it and would like to make it road worthy again.