86 Spider Quad short - #7 fuse

[Carlo_Cardilli@domain.elided]

Ciao Alfisti
I've got an annoying short on the circuit on the #7 fuse on my '86 Spider
Quadrifoglio, and since I'm still waiting for my CarDisc to arrive, I'm
hoping that somebody might be able to e-mail me a wiring diagram or
tips/experience with a similar situation.

The problem was probably created by the PO.  A detachable face cassette
player was installed, and somehow wired through the heater/fan switch (you
need to put the fan switch in the "middle" position to turn the radio on!)
- - when I bought the car I vowed I would fix that, but it deteriorated
faster than I imagined.

The first time I tried to plug in a cellphone in the cigarette lighter I
found out that within a few seconds the following had lost power:
- - cigarette lighter
- - "dash" clock (not on dash but below gearshift)
- - cassette player
- - heating circuit incl. heater fan
- - speedometer (which is the most annoying part of it all).

The #7 fuse was blown, and I noticed that the PO had put a 25A fuse in
there instead of the 8A that's supposed to be in there.  Figured it was
supposed to accomodate the extra draw of the cassette player, and the
combined load of cassette player and cellphone was just too much for the
circuit to handle.  So just put a 25A fuse in #7.

BAD idea.  Now the car wouldn't start.  Immediately pull #7, car drives
fine (except no speedo which is now permanently showing 10 mph).  Over the
weekend I decide I'm going to fix it, so step one was to put an 8A fuse in
#7 just to check that I wasn't imagining things with the earlier no start
experience.  Everything comes back to life, even the speedo.  As I was
pressed for time, I yet again postponed diagnosis for later.

Driving home from work yesterday #7 goes out again as I accidentally press
the fog light switch instead of the driver side window switch.  All of the
above instruments/gadgets go out again.

So now I'm going to do this properly.  Any wiring diagrams for the #7 fuse
circuit on an 86 Spider Quad are welcome, as are suggestions as to where
that darn ground short may be.  If you reply off-digest I'll consolidate
the suggestions and report back to the list later.  Thanks in advance for
any and all assistance.

Carlo Cardilli.
San Francisco

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