Pinto Car Club of America

From my other posts my current dilemma is a non working horn on a former Pinto drag car that I am making street legal.  That is non working using the horn button.  I tested the horn with a portable battery and it does work.  I have kept digging and finally found the wire with connector that originall went to the horn.  The problem is that when the horn button is pushed, the wire going to the horn goes to GROUND potential, not 12 Volts.

According to the dealer schematic I acquired as well as two other books with schematics, the horn button is hot and supplies 12 Volts to the horn via the wire I found.

According to the schematics, 12 volts is supplied from the headlight switch (connector C-25) via a light green and red wire that goes up to the steering column connector (C-26).  I took the plastic covers off the steering column and found the light green and red wire at connector C-26.  Using an ohm meter and probe I have verified that that light green and red wire is in fact at GROUND and not at 12 Volts like the schematic shows.  That light green and red wire then goes to one side of the horn button contacts.  The other side of the horn button contacts is a dark blue wire that via other connectors ends at the horn.

So there are 2 choices for a fix.  1) Get the light green and red wire off GROUND and on to 12 Volts.  2) Use the wire going to the horn as a ground to operate a relay to supply the 12 Volts to the horn.

#1 will probably require taking the center dash out to allow access to remove the headlight switch and attach the light green and red wire to 12 Volts.

#2 will require locating and wiring a 12 Volt source to a relay that is wired up to the horn to provide the 12 Volts to the horn connector.

Wonder if any one else has run into this problem.

Dick