Instrument panel wiring

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Dirk

Member
Joined
May 9, 2013
Messages
18
Reaction score
0
Location
Mesa, Arizona
My Car
1973 Mustang Convertible, 351C 2V (H code), FMX Tran, Ram Air, 3.25 gear, Air Cond, Front Disk Brks, Restored to factory
I have the tach and mounting plate that will replace the idiot lite panel. I also have the circuit board (with tach) to replace the original.

I noticed that the size of the wiring harness plug is a different size and the number of wires if different. Is there somewhere I can get a diagram of the plugs and what goes to each contact? Currently there is a idiot lite panel in it.

 
Because of the differences in wiring, and because of the way the tach is wired into the ignition coil circuit, it's advisable to get the correct wiring harness. I recommend you get in touch with Midlife, a member and advertiser on this forum.

Wiring diagrams are available on this site at:

http://www.7173mustangs.com/misc.php?page=diagrams

 
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Yeah, it is fairly difficult for the average Joe to transform a non-tach underdash harness to tach-configuration. You'll need that 12 pin dash cluster connector (rare as Hen's teeth for Mustangs) and create a new 8 pin connector for the center three-gauge cluster. I can do that and refurbish everything for you for $225, including new fuses, a 2 year no-questions asked warranty/guarantee, and unlimited customer support. Everything will work as Ford originally intended.

You'll also need to replace the headlight harness to one that is tach-configured if you want the ammeter to work in the center gauge cluster.

 
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You're probably too far down the road to do this, but I used a modern tach (original face) from Bob at

http://www.rccinnovations.com

it's $180 if you have the idiot light core still.

and it's easy to connect. I think it was power and a wire to my MSD. It works beautifully. It dropped right in. You keep all your existing wiring.

Also I had bob convert my center ammeter to a voltmeter. He can refresh your gauges while he's at it.

while you're in there, consider redoing the lights with LEDs.

Bob is a straight shooter. Nice guy too.

 
You're probably too far down the road to do this, but I used a modern tach (original face) from Bob at

http://www.rccinnovations.com

it's $180 if you have the idiot light core still.

and it's easy to connect. I think it was power and a wire to my MSD. It works beautifully. It dropped right in. You keep all your existing wiring.

Also I had bob convert my center ammeter to a voltmeter. He can refresh your gauges while he's at it.

while you're in there, consider redoing the lights with LEDs.

Bob is a straight shooter. Nice guy too.

I have a complete instrument panel without the tach (original) and a complete instrument panel with a tach. The problem is not installing it but the fact that they have different plugs. The physical slot on each instrument panel is a diffident length and number of contacts and the connectors on the circuit board have a different number of contacts. I was wondering if anyone had a cross reference of the connectors and what is on them. Maybe I can make a wiring harness adapter. I also have the center console gauge cluster witch I am also going to install.

I have been able to keep this car as close to original as possible except fro 2 items. One the Pertronix magnetic switch in the distributor and the hood graphics being white. I would like to keep it that way as much as possible. All of the upgrades are original parts that were available from Ford when the car was built.

Thanks, Dirk.



Yeah, it is fairly difficult for the average Joe to transform a non-tach underdash harness to tach-configuration. You'll need that 12 pin dash cluster connector (rare as Hen's teeth for Mustangs) and create a new 8 pin connector for the center three-gauge cluster. I can do that and refurbish everything for you for $225, including new fuses, a 2 year no-questions asked warranty/guarantee, and unlimited customer support. Everything will work as Ford originally intended.

You'll also need to replace the headlight harness to one that is tach-configured if you want the ammeter to work in the center gauge cluster.
That would be worth the money but I live in Arizona. I do have a truck and trailer but not willing to drag the car to Florida and back. That would cost a couple thousand dollars I don't have!



You're probably too far down the road to do this, but I used a modern tach (original face) from Bob at

http://www.rccinnovations.com

it's $180 if you have the idiot light core still.

and it's easy to connect. I think it was power and a wire to my MSD. It works beautifully. It dropped right in. You keep all your existing wiring.

Also I had bob convert my center ammeter to a voltmeter. He can refresh your gauges while he's at it.

while you're in there, consider redoing the lights with LEDs.

Bob is a straight shooter. Nice guy too.

I have a complete instrument panel without the tach (original) and a complete instrument panel with a tach. The problem is not installing it but the fact that they have different plugs. The physical slot on each instrument panel is a diffident length and number of contacts and the connectors on the circuit board have a different number of contacts. I was wondering if anyone had a cross reference of the connectors and what is on them. Maybe I can make a wiring harness adapter. I also have the center console gauge cluster witch I am also going to install.

I have been able to keep this car as close to original as possible except fro 2 items. One the Pertronix magnetic switch in the distributor and the hood graphics being white. I would like to keep it that way as much as possible. All of the upgrades are original parts that were available from Ford when the car was built.

Thanks, Dirk.



Yeah, it is fairly difficult for the average Joe to transform a non-tach underdash harness to tach-configuration. You'll need that 12 pin dash cluster connector (rare as Hen's teeth for Mustangs) and create a new 8 pin connector for the center three-gauge cluster. I can do that and refurbish everything for you for $225, including new fuses, a 2 year no-questions asked warranty/guarantee, and unlimited customer support. Everything will work as Ford originally intended.

You'll also need to replace the headlight harness to one that is tach-configured if you want the ammeter to work in the center gauge cluster.
That would be worth the money but I live in Arizona. I do have a truck and trailer but not willing to drag the car to Florida and back. That would cost a couple thousand dollars I don't have!
Would you happen to have a list of the pins on both plugs and what is on each pin. I would be able to pay for that info.

 
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Good for you keeping it period correct. A little extra challenging but extra rewarding too. I believe what midlife does is you pull your existing harness out and send it to him and then he sends it back to you cleaned up and refurbed and whatever else you need on it. He is well respected on the forum for doing this. I imagine he will chime in shortly.

 
Good for you keeping it period correct. A little extra challenging but extra rewarding too. I believe what midlife does is you pull your existing harness out and send it to him and then he sends it back to you cleaned up and refurbed and whatever else you need on it. He is well respected on the forum for doing this. I imagine he will chime in shortly.
I respect anyone that can clean up old wiring! I did some on a B52 back in the day and that was after several modifications and upgrades left a lot of wires in disarray and some that should have been taken out.

In this case I would like to just build an adapter from the old wiring harness plug to the new instrument panel plug. All I need is what signals (volts, ground, sensor...) is on each contact.

I have a set of dealership wiring diagrams but they do not take into account how may variations there were, only each wire from beginning to end.

Thanks

Dirk

 
midlife would need the harness pulled from the car then sent to him where he works his magic.

I restored my engine bay harness a couple of years ago and needed to replace many broken connectors and fix wires and splice repairs in and it was not easy.

really you want to pull the harness anyway to make the modifications correctly and not accidentally cause a short or mis wire something.

you have to pull the dash part to make the electrical and instrument changes anyway so it would pay to go the extra step with a couple more bolts and pull the dash frame out and then pull the harness and ship it off to midlife he will do the job right and installation will go much faster.

 
midlife would need the harness pulled from the car then sent to him where he works his magic.

I restored my engine bay harness a couple of years ago and needed to replace many broken connectors and fix wires and splice repairs in and it was not easy.

really you want to pull the harness anyway to make the modifications correctly and not accidentally cause a short or mis wire something.

you have to pull the dash part to make the electrical and instrument changes anyway so it would pay to go the extra step with a couple more bolts and pull the dash frame out and then pull the harness and ship it off to midlife he will do the job right and installation will go much faster.
I am not going to pull the harness and I am not going to make any modifications to it. I want to make an adapter cable to go between the harness and the instrument panel. If I have to I will manually trace every wire in the harness to figure out where they go. Tracing the wires on the circuit board is easy. Currently I have no electrical problems and the harness looks good. I don't want to create any problems pulling it and then putting it back.

Pulling the whole instrument panel is very easy. I have a whole new one to put in with new circuit board, tach and new LED lights. All I need to do is connect the wires. That can be done very easily by making an adapter pigtail with the wires going to the correct pins on the plug.

Since I have had the car I have only had one major electrical problem and that was caused by someone that purchased a one size fits all headlight switch. It would overheat and blow a 20 amp fuse. I found out the light switch changed in March of 73. If the vehicle was made before April you used the old switch and after March you used the new switch. MAC Auto has both switches and info in the dates.

Dirk.

 
The problem is that you can't simply build an adapter from the 18 pin connector to the 12 pin connector. These pins and connectors are not reproduced (sold separately), nor is there any mates to these connectors. Some of the wires need to be re-routed to the 3 gauge center cluster, some need to be eliminated, and some need to be added. You also have to change wiring at the ignition plug (pink resistor wire) and re-route it as well.

The issue is that not only are you adding a tach, but you need to deal with the alternator lamp (not available on the tach dash) by replacing it with ammeter lines, that need to run from the fuse box.

The 12 pin dash connector is very rare on Mustangs and hard to find. Good luck to you!

 
Good for you keeping it period correct. A little extra challenging but extra rewarding too. I believe what midlife does is you pull your existing harness out and send it to him and then he sends it back to you cleaned up and refurbed and whatever else you need on it. He is well respected on the forum for doing this. I imagine he will chime in shortly.
I respect anyone that can clean up old wiring! I did some on a B52 back in the day and that was after several modifications and upgrades left a lot of wires in disarray and some that should have been taken out.

In this case I would like to just build an adapter from the old wiring harness plug to the new instrument panel plug. All I need is what signals (volts, ground, sensor...) is on each contact.

I have a set of dealership wiring diagrams but they do not take into account how may variations there were, only each wire from beginning to end.

Thanks

Dirk
Maybe is this a little help:

 
Good for you keeping it period correct. A little extra challenging but extra rewarding too. I believe what midlife does is you pull your existing harness out and send it to him and then he sends it back to you cleaned up and refurbed and whatever else you need on it. He is well respected on the forum for doing this. I imagine he will chime in shortly.
I respect anyone that can clean up old wiring! I did some on a B52 back in the day and that was after several modifications and upgrades left a lot of wires in disarray and some that should have been taken out.

In this case I would like to just build an adapter from the old wiring harness plug to the new instrument panel plug. All I need is what signals (volts, ground, sensor...) is on each contact.

I have a set of dealership wiring diagrams but they do not take into account how may variations there were, only each wire from beginning to end.

Thanks

Dirk
Maybe is this a little help:
Yes, that is exactly what I was looking for. This solves a lot of the mysteries!

Thank You.

Dirk.

 
Does your parts car with the tach / gauge package not have a complete harness?

You could get everything electrical working in the parts car first and then just perform a full wiring swap.

I have stripped cars down to just the shells to have them dipped and it is not all that difficult to get the harnesses out and back in.

Leave as much plugged together as possible, make notes, tag everything, and take lots of pictures.

- Paul

 
Does your parts car with the tach / gauge package not have a complete harness?

You could get everything electrical working in the parts car first and then just perform a full wiring swap.

I have stripped cars down to just the shells to have them dipped and it is not all that difficult to get the harnesses out and back in.

Leave as much plugged together as possible, make notes, tag everything, and take lots of pictures.

- Paul
The only wiring harness is in my primary car. That is why I do not want to disturb it. It is working fine with no problems. I have another complete instrument panel with a tach instead of the idiot lites. I have completely disassembled it, cleaned, painted, and mounted the Spedo, gas gauge, and tach in it. I have a new circuit board and a set of LED lights to put in. All I need to do take the original instrument panel out and put the new one in after figuring out the wiring. I already have a wiring diagram for the tach.

Dirk.

 
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