I've been driving(bombing)my '65 all over ever since I finished the engine swap a few months ago. At first, the truck ran with no problems. Then, about two weeks ago, the truck started to misfire severely. I re-routed spark plug wires, replaced spark plug and re-timed the ignition, all to no avail. This weekend, I checked the positive side electrical feed to the coil and found it to be really weak. I had found the problem! I disconnected the engine harness from the firewall bulkhead connector and pulled it apart. I discovered that the two wires for the temp sender as well as the wire for the oil pressure sender had been cut off and the ends taped back into the loom. The yellow and pink wires that ran to the starter solenoid were in good condition, as were the solenoid energizer wire(purple-also to the starter solenoid)and the other yellow wire between the coil and the starter. What the heck!? How could that be? After that I checked the male (cabside) bulkhead connections with a test light and the truck 'on'. They were fine, even the temp and oil connections! I re-built the harness and hooked it all up. The truck started right up and idled clean, but as soon as the tires hit the street, the truck started missing so badly that it stalled. Nursing the truck back into the garage, I touched the coil. Ouch! It was so hot I got a burn! What gives? My question in all of this rambling actually is about using a replacement harness for the whole truck. I do not want to risk another electrical problem with my new motor. I also figure that all new wiring will offer me a dependable ride for years in addition to increasing the old hauler's value. I know that chevy duty sells a replacement harness for all trucks with 12 circuits. Are they worth it? How about ease of installation? Being a novice, I appreciate your help. Oh yeah thanks for reading the pointless part, too. TrustyRusty
Another option is to consider replacing only the harness giving you fits. In this case, the engine compartment harness. ChevyDuty also sells those. Dennis
You could also install one of the wiring kits available. Painless Performance and Ron Francis Wire Works come to mind. One of the less expensive kits go for around $200 and up. Another bonus is that they are super easy to install. Trust me--it only took 1 1/2 days on the weekend and that was with me working half speed. Give it a try.
Hey! When you say you rebuilt your wiring harness, did you replace all the wires going to the coil? I think the pink one (if you're still using the stock distributor) is a resistance wire and if replaced with a regular piece of wire, would send to much voltage to the coil. That might cause it to get hot and short out. I bought a new engine harness from chevy duty, and even though I had to modify it a bit (because it's not the stock motor) it still made life a lot easier. If you're using an HEI ignition, the resistance wire needs to be removed and replaced with a regular that's at least 12 gauge. For my money, replacing the wiring with premade harnesses, etc., is a smart sanity-saving thing to do.
Hey thanks for all of the help! As a matter of fact, I had replaced every wire in the harness with regular wire. With the help of my dad this time, I put in resistance wire and replaced the coil. IT worked like a charm. I'm back on the road for now, but I already ordered a complete replacement harness from CHEVY DUTY; I'll be putting it in real soon. Once again, thanks for all of your help and happy motoring! TrustyRusty
