I was on the NJ turnpike the other day when the engine cut out. I pulled over and checked the distributor and coil, everything checked out. Engine turned over but did not start. I wiggled the main harness and the engine started and ran fine. I have to look for a broken wire or bad connection in the harness. Any color wires I should look at first??? Thanks

You wiggled the main harness or engine harness?

If the 12 pin engine harness ... check the connections at the coil - purple w/ red trace as I remember to the 15 terminal (+).

Next would be corrosion on the pins on the relay board.

Engine harness.

What type engine and do you have the original fuel injection?

Pin one (yellow wire) from the 14 pin connector is the wire for your starter, which obviously works. Pin 8 on the 14 pin connector (black) is the one I'd be looking at. Pin 8 supply's voltage to the ignition coil and the rear blower. The black wire changes to black/red on pin 7 on the 12 pin connector, which runs to the ignition coil.

Which harness are you tugging on to get things to work? When they car randomly shuts off, do you lose the rear blower as well?

I don't know if you have carbs or the original FI system, so this is as far as I can help you.

I have a 1975 1.8L engine with fuel injection. Thanks

Likely you have a connector spade or 2 or 100 that have oxidized over the years. This is the dirty look that connectors get over time. When you giggled the wires likely you moved the offending contact until it made a good connection again.

I've removed connectors and tried to clean the connections either with a small file or hobby knife. You can try a contact cleaner spray but they don't do much for the oxidation on connectors.

Sometimes just removing and reconnecting connectors will do the trick...or make it worse.

Mine did that to me multiple times. Sometimes it would restart after sitting for a few minutes/hours. I finally fixed it by replacing the relay board in the engine bay. Problem disappeared so I took all of the black stuff off the bottom of the relay board to see if I could locate the problem. I found a loose connection from the trace to the fuse holder. I could see where it had been hot enough to melt some of the insulation. I could not see it from the top and the connection (rivet) seemed solid.

YMMV