For those of you that may be considering keeping your original wiring harnesses: check them carefully before making your decision!
Up until this weekend, I've been thinking I would keep the original wiring harnesses in my car. Not any more. With the engine out, I was able to get "up close and personal" with the firewall. When I removed a retaining clip in the middle of the firewall, I found a burn spot on the paint behind one of the wiring runs. During the search for the cause of the burn, I came across a break in the feed to the heater blower (not sure this was the cause of the burn). After removing the blower for a closer look, the insulation on both the power supply and ground wires were found to be cracked at the strain relief on the fan housing - definitely not a good thing. Between these wiring failures, the wire from the fusible link to the starter relay breaking off when I moved it, and several hacked in taps to the harness inside the car, I think it's time for this stuff to leave.
