My under dash resistor wire melted. Bought a new one, but it has bullets on both end. One side goes into the ignition, but the other side doesn't necessarily go into the firewall harness. I'm guessing I could try to splice in the wire, but people online suggest not to do that, as it'll affect the resistance. I have maybe about 1/2" of burned wire remaining that I could crimp a female bullet on, or, preferably, I'd like to pull the wire out of the harness end so it would be a cleaner install. Any tips?
Yes. My replacement wire is similar to that one. One side plugs into the ignition; how do I plug the other end into the harness?
Explain 'ignition'. Is the replacement resistor FORD or aftermarket? If no one has been in there before messing with it, the FORD part should be a straight install. The incorrect resistance will at some point burnout the coil and points, if it starts.
Ignition as in the ignition switch that one puts the key into. The pink wire melted from there. It goes into the harness at the firewall. This is the wire. It looks the same as the OEM one you posted. It isn't a straight install, because there is no female end on the harness, or if there is, I need help figuring out how to access it.
You are yelling so I can't help you. MISS CLEO cut my account so I cannot see where you are or describing. IGNITION now equates to IGNITION SWITCH. We are making progress.
First order of business would be to find the reason for the excessive resistance that caused the original wire to melt
Ford fell in love with these 'resistance' wires in the '60s and by and large they were reasonably reliable. But they do fail on occasion. Unlike the usually firewall mounted wire-wound ceramic resistors used prior, they are a PITA to replace. They do generate quite a bit of heat in normal operation and that can take a toll on connections and insulation as well in the rest of the circuit. Add in that your car is 64+ years old and things like wire insulation and connections can start getting marginal from just age. With that said, troubleshooting the remaining wire before repair should expose any downstream issues. I'll note that I don't have a '60 Comet wiring diagram, so I'm assuming this is wired as 'typical' to most Ford products of this era. The circuit as-designed is a single wire going directly from the ignition terminal on the switch to the + terminal on the coil. The resistor wire is installed in series in this wire. There should likely be a second wire tapped into this wire as the resistor bypass, only active when starting the car. Not knowing your level of expertise in wiring troubleshooting, I'll spell this out in the simplest terms possible. First thing I'd do is cut out the burned portions, being careful to leave enough wire at the bulkhead grommet to be able to splice onto it. I'd cut it just above the 'blister' shown in the pic, then strip the blister off. Examine the bare wire strands. If it's dull and/or brittle, it probably got hot enough to remove the annealing in the copper and it'll be prone to breaking. If the wire will break with just a few times of bending it back-and-forth, that's the indicator. Next, verify that the wire does go to the coil using an Ohmmeter. The meter should read zero Ohms or very close to it between the two ends. Move to the starter solenoid. It should have two smaller terminals, the one on the battery side should be marked 'S'. The other one should have an 'I' next to it. This 'I' wire should read to both ends of the pink wire, also with a zero reading wanted and is the resistor bypass. Check the exposed parts of these wires in the engine compartment for cracked insulation and broken strands, repair if needed. So far so good? Let's move on to the repair... Splice a new piece of wire onto the bit protruding from the bulkhead grommet using a crimp sleeve. If the wire is prone to breaking, use at least two layers of shrink tube for strain relief, one layer in any case. DO NOT SOLDER! Solder will start 'moving' at temps as low as 300 degrees, it doesn't like heat. It will also make the wire more prone to breaking. For a proper crimp, read this... Technical - Crimping Tutorial | The H.A.M.B. (jalopyjournal.com) Splice the resistor wire in using the same method, you should be good. One last thing; check your coil primary resistance between the + and - terminals on the coil. You should get a reading of about 1.5 Ohm, with a tenth or three on either side being acceptable. Above or below that number, you may have a failing or wrong coil. Ideally, the coil resistance as measured should be roughly the same as the resistance in the resistor wire. Any questions, just ask!
Thank you for your detailed answer! I replaced the engine side of the harness, as it was frayed, and looked like it was melting too. This was fairly easy, all things considered. There is no second wire as a resistor bypass. From the ignition switch the resistor wire goes to the bulkhead; on the other side are two wires, one going to the "I" on the starter solenoid, and one going to the coil. Thanks again! You are the man!
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