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The wiring to my tach was cobbled together, which why I'm re-doing the whole thing. The wires on the new harness won't connect to my tach as is. My tach has 2 studs and a hole to which the brown wire screws into.
If you look at the pic you'll see a fuse housing. The other end of that housing hooks up to the back of the tach. The question is where can I find those wires and connectors? Also the Orange clock wire has a connector. The back of my tach is just studs.
I'm willing to purchase these connectors and wires if anyone knows where to get them.
There is a separate wire harness for the tach. The tach lead-in is shielded to prevent radio interference. All the usual suspects sell repros.
FWIW I used a Brown wire that I ran from the tach to a blank slot in the firewall connection block and then ran a corresponding brown wire from the inside of the block into the dash harness. I makes for a nice clean installation. I'm not sure what the factory did in 68. If I recall correctly the tach lead is shown as a brown wire in the 68 wiring diagram (not the main diagram, I remember one specifically for the Rallye Pac). I think they ran the single fused brown wire right through the firewall. Maybe that shielded wire Joe shows above is brown under that insulation
I'm a dumbass because I haven't fused it yet, but someday I will. I don't get any radio interference.
Last edited by allyolds68; April 28th, 2016 at 12:50 PM.
Yes, the fused brown wire (2 amp) goes through the firewall via a connector at the fuse block for cars that originally came with the rally pac/tach. It then resumes on the engine side of the firewall and goes to the negative side of the coil. For '68 and '69, as I recall, there wasn't any shielding that went with it. The shielding started with model year 1970.
Since my '68 didn't come originally with a tach, I ran a fused continuous brown wire through the wire grommet on the far driver side of the firewall and then to the coil.
Pictured below are the connections to the back of an original tach/clock.
Yes, the fused brown wire (2 amp) goes through the firewall via a connector at the fuse block for cars that originally came with the rally pac/tach. It then resumes on the engine side of the firewall and goes to the negative side of the coil. For '68 and '69, as I recall, there wasn't any shielding that went with it. The shielding started with model year 1970.Randy C.
That must be why I wired it the way I did. I'm sure you answered this 10 or 12 years ago when I probably asked the question on ROP
Pictured below are the connections to the back of an original tach/clock.
Randy C.[/QUOTE]
So does the gray wire in your pic have the other end of the fuse housing? And where is that brown wire on my harness pictured above?
I called ALL of the repro people and NONE have just the wire with that top fuse housing. I'd have to buy the entire tach harness which comes with the shielded wire Joe was talking about.
The grey wire is a pigtail that connects into the grey wire harness behind the dash (it can be seen on the left side of the picture). It provides power to the lights in the dash.
The orange wire is 12V power for the clock.
I'm not sure I see the brown wire in your harness, in which case your harness might be for a car without a tach. In that case, I would just run another length of brown wire as I did with my '68, through the wire grommet on the far left side of the firewall and then over to the coil. You may have to snip the fuse housing and buy a complete housing for the 2 amp fuse.
Randy C.
Last edited by rcorrigan5; April 28th, 2016 at 06:27 PM.
I'm not sure I see the brown wire in your harness, in which case your harness might be for a car without a tach.
This question has come up in the past and the vendor's response was that the tach lead was not part of the 68 harness so it wasn't included. You have to buy the tach wire separately. Pretty poor answer when you're selling a Rallye Pac Wiring Harness .....
Basically they re-arrange the wires in the gauge plug and call it a Rallye Pac Harness. They plug the pigtail into the purple connection and it's a MT Floor Shift harness
I don't see the green wire in the ignition connection so at least you don't have to cut that one like you usually do to convert a regular harness to a Rally Pac harness.
If you have a Factory Service Manual the Rallye Pac wiring diagram is on page 15-31. I think the wire colors are labeled but the diagram is not in color like the standard wiring diagram. I should scan it from my hard copy because the version I have from Wild About Cars isn't readable
Last edited by allyolds68; April 29th, 2016 at 06:38 AM.
Tonight I stand humbly corrected. I was working on my '69 4-4-2 (came from the factory with the rallye pac) and I discovered the opposite of what I had stated previously. The brown wire from the tac to the negative side of the coil is separate from the wiring harness in my '69. I didn't know that - I thought it was an integrated part of the wiring harness. It isn't. The brown wire runs from the tach, across the top of the gauge & speedo pods, and then forward through the wiring grommet on the driver side of the firewall and then over to the coil.
The separate harness you received for the tach should work perfectly. I'm still certain on the shielding - that didn't start until model year 1970. But you could run your shielded wire ( has extra protection that the 68-69 wire did not) with a 2 amp fuse from the tach, through the grommet and over to the coil and that should do the trick.
I did call up American Autowire and even they are perplexed as to how I hook my tach into the fuse housing on their harness. The tach wire is embedded into this harness. it goes through the fuse block and attaches to the engine harness on the other end and hooks right up to my HEI distributor.
I think the solution is I need to buy the entire tach wiring harness I posted above (and Joe too) just for that little short wire that screws into the back of the tach. it has the top of the fuse housing. I can't fins just that little wire anywhere!
The orange clock wire and the grey wire will connect onto the 2 post on the back of my tach after I put a spade like connection onto those post.
I'm finally going to install the dash harness this weekend!!!
Sorry to resurrect this thread--just bought and I'm installing American Autowire factory fit engine harness on my 1969 442. I ran into some confusion--any idea what the brown wire supposed to be hooked to on my coil?
My harness from American Autowire was custom made for a HEI setup, so I can't help.
If no one has an answer here call AA in the morning. I did several times when I rewired my car. Give them the part number and they pull out the book and tell you exactly what it goes to. They're VERY helpful!
Thanks! I just don't want to hook it up wrong. When I got the car, after someone else hacking on the wiring for 47 years---it looked like a beaver wired it. I'll give them a call in the AM.
My harness from American Autowire was custom made for a HEI setup, so I can't help.
If no one has an answer here call AA in the morning. I did several times when I rewired my car. Give them the part number and they pull out the book and tell you exactly what it goes to. They're VERY helpful!
I emailed them late last night and had an answer this morning:
What is the brown wire on harness 11590 for, near the coil?
Good day Bryan,
Thanks for your inquiry, the brown wire with the flag terminal is for a factory tach and is installed on the (-) side of the coil. This wire sends the rpm signal to the Tach.
Thanks again for your inquiry and have a great day.
Ray
Interestingly, my original factory dash harness does not account for this. I'll hook it up, and when I get around to the dash harness, I'll utilize it.
Ah, but if I buy their $600 dash harness, it would
I wouldn't have to run that pesky wire through the grommet on the firewall. The horror!
I'll rephrase that. Their harness isn't a duplicate of the factory harness. As this thread (and the CSM, and the PIM) points out, the factory used a totally separate tach feed harness that was not integrated into the underhood harness. I have no idea why they chose to built this harness incorrectly. Yeah, it's easier to install, but it isn't correct for a restoration, and frankly, they've lost out on the option to make more money by selling the correct separate tach harness.
I'll rephrase that. Their harness isn't a duplicate of the factory harness. As this thread (and the CSM, and the PIM) points out, the factory used a totally separate tach feed harness that was not integrated into the underhood harness. I have no idea why they chose to built this harness incorrectly. Yeah, it's easier to install, but it isn't correct for a restoration, and frankly, they've lost out on the option to make more money by selling the correct separate tach harness.
April 28th, 2016, 10:45 AM
