Hey guys.. long time no post. The year of the car is 1978 if that is needed for wiring info. My car has been undergoing an extremely long process, and I'm finally starting to work on the wiring on it. I'm putting an A9L computer in it (from fox body Mustang), and I need to splice some wires from my existing harness into the A9L wiring harness. The harness I have wants wires for these 3 settings.. run only, run and crank, and crank only. I think I found a wire for run only, and run and crank, but I haven't found one for crank only. Also, I think I need to find a wire to splice into for something regarding the brakes? Wiring isn't my strong point, so going through my 3 Mustang II manuals I have didn't help my cause. Let me know if I'm not making any sense, because I'm having a hard time wording it that sounds right to me. Thanks for any help you can give me, and if this has been discussed already, please point me to where I need to go, I wasn't able to find anything.. but it's likely it was right under my nose and I missed it. Gael
I can run down to my parents place in the am and see if I can find what I did with the Original Ford shop manuals I have for my 78
For Crank Only use the wire that engages the starter solenoid, that's +12vdc when cranking only. You shouldn't need the brake input, but if you really want it just tap off of the brake switch. The brake switch is probably the brake light ground but I could be mistaken. Use a DVOM to test that. Does the A9L want a ground or +12vdc for the brake input? If the switch is the opposite of what you need you can use a relay, have the brake switch bias the relay and provide whatever input the ECU needs.
