Greetings,

Had trouble starting 90 F150 4.9, traced it down to broken wire but not sure exactly where it's supposed to go. It's coming out of the loom next to the plug that goes into the coil, a red (with green strip - I think) that clips into a black wire that goes ?? Couldn't find the other end of the black wire and my manual isn't real clear.

Thanks

 

The red wire with a light green stripe is your primary ignition feed. It is supposed to be +12 volts in run or start. It goes to the + side of the coil primary, to the TFI module, to the coil for the EEC power relay, and to an RFI suppression capacitor mounted close to the coil.

Black wires in the harness are ground wires. You should definitely not connect the R/LG wire to any black wires.

It sounds vaguely like the RFI cap has fallen off and the remaining wire is dangling there. Unless this shorts to ground, the truck should still run. But I can't tell any more from the information given.

Use a test light, verify that there is +12 volts on both sides of the coil primary, and go from there...

 

My first thought also was that it was a ground, but checked it with test light and it had power. The R/LG wire is the one in the harness and then it clips via a connector to the black wire which is broke. Just do not see anything (obvious) that it would connect to. Where exactly is the RFI cap?