Thunderscrash 10 Report post Posted November 1, 2013 Been a little while since I was last here but I've been a busy beaver working away on my 69 and I'm to the underdash harness. Somewhere over the last 44 years the underdash harness has gotten pretty mangled. I bought a new (to me at least) harness at Carlisle earlier this year and it seems to be in great shape. Only thing that appears to be wrong so far is that someone cut out the ignition pigtail. I ordered one from Cj's and I am having an issue with what wires I need to connect. From the harness where it appears the ignition pigtail should be I have a Big yellow wire Green w/red trace wire Brown wire Red w/ blue trace wire Black And an orange wire, purple wire, and a big black w/green trace wire that all splice together and come out as a black w/ green trace wire. I assumed that I would just need to match them up color to color with the new pigtail but the colors do not match. The new pigtail has The big yellow A big black w/yellow trace Red w/blue trace Purple Red w/ white trace And the peach colored resister wire with a green w/red trace wire connected at the same point. I've tried searching around the best I could but I can't seem to find an idiots guide and I'm about to give up haha can anyone help me out? Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted November 2, 2013 Oh boy. Someone cut off the ignition wires above the factory splice on the ACC line (big black/yellow wire). There are two ignition wire set-ups: one for a tach dash and one with a standard dash. Since your harness doesn't appear to have the peach colored resistor wire, here's the set-up for a tach ignition switch. Big yellow connects to big yellow (duh). Green/red goes to green/red. Orange, big black w/green trace and purple wire are spliced together and join the big black w/yellow trace. You should have a purple wire (multiple stands)---this is probably what you are calling a black wire or possibly the brown wire. That goes to purple wire on ignition. Red/blue goes to red/blue Red/white on ignition was never used; the ignition switch is a general purpose switch that can be used on other Fords. You can ignore it. That leaves the peach (pink) resistor wire on the ignition switch and either the brown or the black wire on the harness. I know of no black wire going to the ignition on a 69, so your color is off. My guess is that one of your two wires has thick insulation and is "spongy"; if so, that's the pink resistor wire. You cannot solder resistor wires together, so you can only crimp them. If you do have a resistor wire, then the harness is for a standard dash, not a tach dash harness. The tach dash harness has a two prong male/female plug that has the pink resistor wire as the male and a two wire affair going to the female; this plug goes to the tach itself. Hope that helps. Quote Share this post Link to post Share on other sites
Thunderscrash 10 Report post Posted November 2, 2013 Midlife, you are the man. That is exactly what I have been needing. My car is a none factory tach dash and I was told the harness is none tach as well but I will get it all hooked up tomorrow. Thank you very much! Quote Share this post Link to post Share on other sites
Robsterthelobster 0 Report post Posted January 22, 2021 @Midlife@midlife I know this was years ago ^ but this is exactly the subject I could do with some answers on myself and you seem to be just the person, my car is a 70 fastback with standard dash, no tach, somebody has been playing with my wiring and iv been trying to work it all out and agree it goes, namely the large black and yellow wire, green with red tracer wire, and the two wires that come out of the back of the gauge cluster plug? I need to know where exactly to connect them? Correct me if I'm wrong but I think I'm right in saying the black and yellow wire goes direct to live? The other three wires iv no idea? Any help would be greatly appreciated. Thank you in advance Quote Share this post Link to post Share on other sites
danno 128 Report post Posted January 22, 2021 As a person with a 69, I know how they work. I am not sure about the 1970. I put together a schematic of the under dash wire harness. It shows what every wire is and the color of it. The schematic is in 3 pages; left( everything to the left of the steering column), center ( all wires between the steering column and radio) and right ( all wires to the right of the radio). If you print each on a 8.5 by 11 sheet, all three can be taped together to make one large schematic of the harness. YOur problem sounds like it is in the left side. There is a solder connection in the harness above the light switch. This is probably what you are working on. It has a large black wire with a yellow stripe, a big yellow wire, and 2 smaller black wires with yellow stripe. Look at the schematic. I think you are working on the junction with a red circle. Let me know if this helps. MUSTANG NO TACH UNDER DASH MID.doc MUSTANG NO TACH UNDER DASH RIGHT.doc MUSTANG NO TACH UNDER DASH LEFT .doc Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted January 22, 2021 2 hours ago, Robsterthelobster said: @Midlife@midlife I know this was years ago ^ but this is exactly the subject I could do with some answers on myself and you seem to be just the person, my car is a 70 fastback with standard dash, no tach, somebody has been playing with my wiring and iv been trying to work it all out and agree it goes, namely the large black and yellow wire, green with red tracer wire, and the two wires that come out of the back of the gauge cluster plug? I need to know where exactly to connect them? Correct me if I'm wrong but I think I'm right in saying the black and yellow wire goes direct to live? The other three wires iv no idea? Any help would be greatly appreciated. Thank you in advance Not sure that I follow what you're describing. Best to take some pictures and e-mail me if you can't figure it out with Danno's schematics. BTW, Danno is my electrical doppleganger. Quote Share this post Link to post Share on other sites
RPM 1,190 Report post Posted January 22, 2021 36 minutes ago, Midlife said: Not sure that I follow what you're describing. Best to take some pictures and e-mail me if you can't figure it out with Danno's schematics. BTW, Danno is my electrical doppleganger. Hmm...I certainly hope you mean in talent, and not looks. 1 Mach1 Driver reacted to this Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted January 22, 2021 No one can look as pretty as me! 1 RPM reacted to this Quote Share this post Link to post Share on other sites
danno 128 Report post Posted January 22, 2021 12 hours ago, RPM said: Hmm...I certainly hope you mean in talent, and not looks. I think it is marginally with respect to talent, certainly cannot be the looks. 1 RPM reacted to this Quote Share this post Link to post Share on other sites
danno 128 Report post Posted January 22, 2021 Randy, is there any difference between the underdash harness of 69 to 70? Do they use different connectors for the ignition switch? I thought there was a difference in under hood harness, but I am not sure about that either. I know the side lights and headlights are different, which is why maybe the underhood is different. Robster, can you describe the problem you are trying to solve. Quote Share this post Link to post Share on other sites
aslanefe 333 Report post Posted January 22, 2021 53 minutes ago, danno said: Randy, is there any difference between the underdash harness of 69 to 70? Do they use different connectors for the ignition switch? I thought there was a difference in under hood harness, but I am not sure about that either. I know the side lights and headlights are different, which is why maybe the underhood is different. Robster, can you describe the problem you are trying to solve. Ignition switch connector for 69 and 70 are different. Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted January 22, 2021 Oh, there are so many differences. 70 has different ignition switch, and different breakout position of turn signal switch. It has a massive section going out to the starter solenoid, so many wires are eliminated from the fuse box junction for the headlight harness. The 70 also has RUN-only fused lines running through the harness. Rear tail light harness connectors are different as well. The only good thing about 70's is that the headlight harness is identical for tach and non-tach dashes, but there is a variant for the Mach 1 for the sportslamps. 1 danno reacted to this Quote Share this post Link to post Share on other sites