hey guys, HITHERE am wondering it is possible to run HITHERE 7730 ECM and wiring harness in HITHERE car that was originally HITHERE 165. Specifically, my 89 formula HITHEREHITHEREHITHEREHITHEREHITHEREHITHEREHITHEREHITHERE. HITHERE pulled the 165 harness and ecm out and put HITHERE harness from HITHERE 91 in it along with HITHERE 7730 ECM with an Ed Wright chip. My question is this..... Will the 91 harness plug right into the bulkhead connector on the firewall with no modifications??? or is there some repinning that needs to be done. My car starts and runs fine with the 7730 in it, but the reason im asking is because HITHERE keep toasting alternators left and right. Any help would be greatly appreciated.

 

Toasting alternators usually means you've got some loose wires or just high resistance from old exposed wires. I'd check the contacts at the distrib block (next to battery), the starter solinoid, and the battery ternimals. Use some coca-cola or backingsoda in water to clean the contacts and then dry, dielectric grease the contacts and measure the resistance. You'd be amazed what a loose wire can do to a nice new "140 amp" alternator. I'm on my 3rd alternator, this time the wires on the solinoid are good and clean, it's been working for a couple years now.

 

so, the 91 TPI fbody harness will plug straight into the bulkhead connector on my 89(L98) formula and everything will still be functional? The reason i suspect the ECM swap is because the car will run ok for about 20 mins or so....then all of a sudden the alternator stops charging......its done this on 3 different alternators and i doubt oreilys is gonna warantee another on for me. Its almost as if the alternator dies after the motor warms up and goes into closed loop or something....i dont know there may not be a connection. I just need to know if the 91 harness might be causing a problem in my 89.