DeTomaso Mailing List: July 2001, Message #175

In a message dated 7/7/01 18:12:38, catman351@digitalputty.com writes:

<< Some rudimentary troubleshooting ensued and I found it was the Fiamm
supplied relay that was the culprit, essentially a "locking" relay
once energized. In fact, it fell apart (gee, wasn't this a discussion
on the listserv about poor wiring emanating from Modena?) So, I
replace the horn with some of my stock of auto relays (Made in China
no less under the sobriquet "BLAZER") Well, lets hope the ChiCom made
unit holds up better than its Italian counterpart. And so, it did!
After several "beeps" (or should I say "toots" from the bi-toned
Fiamm trumpets), I pronouced the first circuit on #2428 to be
operational. >>

>>>Congrats, Cal.

However, your aftermarket horn relay isn't necessary--the Pantera's wiring 
harness already incorporates a horn relay.  When you do the beep-beep thing 
with the horn switch, power passes through the stock relay (located on the 
relay panel, either under behind the glovebox on early cars like yours, or in 
the driver's side footwell on later cars) and then runs to the horns.  All 
you need to do is hook the stock horn wire (white, if memory serves?) to the 
"+" terminal on the compressor, and fabricate a ground wire from the "-" 
terminal to the body, and you're done.

Wiring the entire car will be MUCH harder if you continue to duplicate 
existing components! :>)  Keep up the great work and thanks for keeping us 
posted! :>)

Mike