Cantedvalve 128 Report post Posted September 7, 2018 I have 1970, and I have found the resistor wire in the harness from the connector that plugs to the ignition switch to the gauge feed harness. It is a spongy light pink color. Is that resistor wire IN the ignition switch? Meaning on the switch side of the connector. If I wanted to eliminate it, do I have to mess with the switch or just the harness it plugs into? I may no need to do it. I got an extension harness and spliced in a relay. I just don’t fancy running more wires under the dash if I can just replace one. Now is a good time to do it too. Quote Share this post Link to post Share on other sites
1969_Mach1 333 Report post Posted September 7, 2018 You found the resistor wire that goes to the original ignition coil. I would leave it in the harness and simply disconnect it at each end if you're using some type of aftermarket ignition system and no longer need it. Quote Share this post Link to post Share on other sites
barnett468 418 Report post Posted September 7, 2018 ok, if it runs all the way to the back of the switch, you can cut it around 3" away from the switch then splice into it then run that under your hood. if there is a short lead on the back of the switch that the pink wire plugs into, you can just unplug that and tie into that short lead. having only 3" of resistor wire will not have a significant affect on the voltage. the longer the resistor wire, the more resistance it has, and thereby the more it will drop the voltage. For example. if the resistor wire is 30" long and drops the voltage by 3 volts, 3" of resistor wire is only 10% of that length and will therefore drop the voltage by .333 volts...i think, kinda sorta. Quote Share this post Link to post Share on other sites
Cantedvalve 128 Report post Posted September 7, 2018 The pink wire in the switch doesnt look or feel like the resistor wire in the harness. I'd say it isn't resistor, so I could take out the resistor wire completely if I chose. I'll look at the harness and see where I want to go. Quote Share this post Link to post Share on other sites
69ShelbyGT350H 61 Report post Posted September 7, 2018 Normally in a non-tach car, the resistor wire runs from the ignition switch connector to the firewall plug. Here it is joined with a brown wire that comes from the starter relay. This brown wire is what supplies the coil/points with the full 12v for startup. On a Tach car, the resistor wire runs from the Tach to the firewall plug. Again, the brown wire is used to get the full 12v (battery voltage) for startup. Edit: As Midlife has indicated, this is for the 69 only. 70 is different. Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted September 7, 2018 No...no....no. On a 1970. the pink resistor wire starts from the fuse box and goes out to the engine gauge feed plug on a non-tach dash. On a tach dash, it runs from the tach plug out to the engine gauge feed plug. On a 1970, the RUN-only line is the outer-most wire next to the large yellow wire, with only 2 wires on that side. On earlier models, (69 and below), the pink resistor wire will join in that pin with the RUN-only line. On a 1970, there is another resistor wire that is shared with the large black/green wire directly opposite of the large yellow wire: that is for the constant voltage regulator input in the dash cluster. There's another resistor wire, typically violet, that goes to the green connector for the fuse box for the alternator indicator lamp. CV: please indicate what pin location you believe the pink resistor wire starts from on this ignition switch. In answer to your question, no, there is no resistor wire on the ignition switch side of the connector itself. Quote Share this post Link to post Share on other sites
69ShelbyGT350H 61 Report post Posted September 7, 2018 2 minutes ago, Midlife said: No...no....no. On a 1970. the pink resistor wire starts from the fuse box and goes out to the engine gauge feed plug on a non-tach dash. On a tach dash, it runs from the tach plug out to the engine gauge feed plug. On a 1970, the RUN-only line is the outer-most wire next to the large yellow wire, with only 2 wires on that side. On earlier models, (69 and below), the pink resistor wire will join in that pin with the RUN-only line. On a 1970, there is another resistor wire that is shared with the large black/green wire directly opposite of the large yellow wire: that is for the constant voltage regulator input in the dash cluster. There's another resistor wire, typically violet, that goes to the green connector for the fuse box for the alternator indicator lamp. CV: please indicate what pin location you believe the pink resistor wire starts from on this ignition switch. In answer to your question, no, there is no resistor wire on the ignition switch side of the connector itself. Sorry, should have read the subject better. My comment is from the 69 wiring manual. Quote Share this post Link to post Share on other sites
barnett468 418 Report post Posted September 7, 2018 6 hours ago, Midlife said: No...no....no. On a 1970. the pink resistor wire starts from the fuse box and goes out to the engine gauge feed plug on a non-tach dash. On a tach dash, it runs from the tach plug out to the engine gauge feed plug. On a 1970, the RUN-only line is the outer-most wire next to the large yellow wire, with only 2 wires on that side. On earlier models, (69 and below), the pink resistor wire will join in that pin with the RUN-only line. On a 1970, there is another resistor wire that is shared with the large black/green wire directly opposite of the large yellow wire: that is for the constant voltage regulator input in the dash cluster. There's another resistor wire, typically violet, that goes to the green connector for the fuse box for the alternator indicator lamp. CV: please indicate what pin location you believe the pink resistor wire starts from on this ignition switch. In answer to your question, no, there is no resistor wire on the ignition switch side of the connector itself. I knew you would know. Quote Share this post Link to post Share on other sites
69ShelbyGT350H 61 Report post Posted September 8, 2018 53 minutes ago, barnett468 said: I knew you would know. I was trying to help, whats your excuse? Quote Share this post Link to post Share on other sites
Cantedvalve 128 Report post Posted September 8, 2018 I found an older post here where someone mapped out the wire colors in the switch. See here: So I was running off that information. You can see pink wire in the switch is marked as ignition. I have that pink wire in my switch. It doesn’t look like the resistor wire, so I am assuming for the moment it is not. Unfortunately, the diagram I have doesn’t show the colors in the switch, just the plug that plugs into the switch. And my diagram is for a tach car. Seeing as I lacked this information for my car, I started scouting around for other Ford diagrams. I found a Bronco and it has the resistor wire coming from the ignition plug. I am going over there tomorrow to take a look at my harness. Here is a picture of my switch's wires. Randy, my switch has 7 wires instead of 6 Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted September 8, 2018 Well now...that is quite unusual. Has your ignition switch been replaced? I suspect that is it has, and is from another vehicle. The third wire, red/white, is for a proof-out circuit for the oil pressure indicator lamp; if your underdash harness does not have a matching wire, that's perfectly OK. I have never heard of a resistor wire in the ignition switch itself; you can simply test it by measuring continuity between the pin and the rivet on the switch itself, but you'll have to pull the ignition switch to get to it. Look carefully at the pink wire insulation, somewhere you should see "resistor wire do not cut" if it is a resistor wire. Here's a link to another switch that also has that pink wire...no mention of a resistor wire. https://classiccougarcommunity.com/forum/viewtopic.php?f=3&t=8943&p=91633&hilit=1970+ignition+switch#p90134 Quote Share this post Link to post Share on other sites
Cantedvalve 128 Report post Posted September 8, 2018 The pink wire in the switch doesn't have anything on it... it is very thin... I'd say no more than 18 gauge. Yes, I did have to replace my ignition switch about 20 years ago. Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted September 8, 2018 I'd say you're good to go, Jim. Errr,,,let me rephrase that...you're good only wearing sunscreen...*G* Quote Share this post Link to post Share on other sites