73 Tach and gauge wiring

[Fastang]

I'm getting ready to transfer the center gauge cluster and speedo/tach cluster from a 73 donor car to my 73 that isn't equipped with them. Will the under dash wiring harness in my non tach/gauge cluster 73 have the plugs to connect the Center gauges and tach or do I need to pull the whole interior harness too?

 

[OMS]

You need to swap the wiring too

 

[Carolina_Mountain_Mustangs]

I'm getting ready to transfer the center gauge cluster and speedo/tach cluster from a 73 donor car to my 73 that isn't equipped with them. Will the under dash wiring harness in my non tach/gauge cluster 73 have the plugs to connect the Center gauges and tach or do I need to pull the whole interior harness too?

I just did this on a 73 vert with air and the previous owner had added gauges and tach and had hacked the harness to pieces and nothing worked. The AMP meter in the gauge cluster got so hot it melted the whole plastic pod. It took months of searching to find the correct wiring and you have to pull it all the way to the headlights. The connections on the engine are different for instruments than idiot lights. Idiot lights are safer you don't have time to look at gauges unless you are stopped.

Good luck it is easiest to pull the entire dash out in one piece and replace the harness and put it all together outside of the car.

While the dash is out you might as well replace the heater core and insulate the cowl, he it never ends.

David

 

[TheRktmn]

Contact Randy at Midlife Harness Restoration http://midlife66.com/harnesses/welcome.html

He can get you wired.

 

[EBSTANG]

Contact Randy at Midlife Harness Restoration http://midlife66.com/harnesses/welcome.html

He can get you wired.

:+1: Randy can hook you up with a restored harness and will take yours as a core. Very reasonable.

 

[midlife]

Yeah, I have 1973 tach's in stock. Send your underdash and headlight in, and it'll cost you $325 plus another $50 if you need the center gauge cluster harness. Two year warranty, no questions asked, plus instructions and spreadsheet schematics for putting it all back together.

Easy Peasy!

 

[Fastang]

Man, I was afraid you guys were going to say that! oh well, I know what I need to do now.

Thanks for the info.

 

[EBSTANG]

Man, I was afraid you guys were going to say that! oh well, I know what I need to do now.

Thanks for the info.

Hey, atleast you'll know that what's behind the dash is done, which is more than most of us on here can say. Removal may sound intimidating but once you spend the 10 minutes to take the dash apart (that's all it really takes) removal of the harness is pretty straight forward...just unplug it all. It's a good move.

 

[Bill73Ragtop]

If you consider the cost and time needed to track down and repair a melted down electrical system or - god forbid - a fire - the price for Midlife to properly set it up for you is negligible in the long run.

 

[73pony]

Yeah my harness under the dash is a disaster. I am trying to figure out where everything goes and how it goes and why the PO did some strange things.

 

[Fastang]

Yes I know. All of you are right. I'm not intimidated by the work needed it's the time needed. I'm getting this thing ready for the Hot Rod Power Tour and I'm leaving June 9th. I'm rebuilding front and rear suspension, swapping motors, converting to 5 speed trans, adding 9"posi w/disc, convert non a/c to a/c, and cleaning, repainting, rewiring, repluming, refurbing all these areas as necessary. So as the song says, I have a long way to go and a short time to get there. It just may have to happen that I don't have tach and gauges on the HRPT.

But thanks guys.

 

[73pony]

That's a lot to get done. I just converted from FMX to T5 myself. It is not too bad. Just a lot of tight work getting the clutch pedal mounted up under the dash if you don't already have one there. Also, be sure you have an manual with correct torq specs and a good (accurate) torq wrench. A trans jack would have been handy but I was able to wrestle the old FMX out from under the car and between the headers without much problem and then wrestle the T5 back up into place. Worst part was trying to hold the T5 in place with one hand and get the trans mount in place under it.


I did have to drop the exhaust from the headers back to the mufflers though and the driveshaft had to be shortened by 15/16"

 

[secluff]

As simple as our cars are compared to a 2016 Mustang, there is still a lot of complexity in the wire harness's. "Murphy's Law" states that anything that can go wrong will, and usually does. With the newest of our cars now 43 years old, sending your wire harness to midlife is better than insurance. I've been to salvage yards "Parts Gathering" and have seen some unbelievable electrical repairs. House type wire nuts, yellow and crumbling paper masking tape on splices, melted wires where there was nothing on the spice, and some big time butchering where all those K-Mart blue light special radio's were installed! An under dash fire is a lot harder to extinguish and if at home in your garage, then you've got an even larger safety issue.

One of my non tach Mach 1's is off the road now waiting for my money tree to mature. When I go back with the tachometer cluster, the wire harness will definitely be going to Midlife. The peace of mind you'll have knowing your "Money Pit" is not going to burn to the ground is worth the money spent!!

 

[Fastang]

That's a lot to get done. I just converted from FMX to T5 myself. It is not too bad. Just a lot of tight work getting the clutch pedal mounted up under the dash if you don't already have one there. Also, be sure you have an manual with correct torq specs and a good (accurate) torq wrench. A trans jack would have been handy but I was able to wrestle the old FMX out from under the car and between the headers without much problem and then wrestle the T5 back up into place. Worst part was trying to hold the T5 in place with one hand and get the trans mount in place under it.


I did have to drop the exhaust from the headers back to the mufflers though and the driveshaft had to be shortened by 15/16"

Thanks for the info. I'm swapping from a 3 speed manual so I have the pedal. I've read a lot of different posts where guys have and have not had to shorten the drive shafts so I'm expecting the worse. I also have a c4 drive shaft I can use to (not sure if it's different). Lucky for me I have a good friend that has a lift in his shop I can use to do all this, I'll likely pay dearly for it later by having to help him work on his Chevy.

As simple as our cars are compared to a 2016 Mustang, there is still a lot of complexity in the wire harness's. "Murphy's Law" states that anything that can go wrong will, and usually does. With the newest of our cars now 43 years old, sending your wire harness to midlife is better than insurance. I've been to salvage yards "Parts Gathering" and have seen some unbelievable electrical repairs. House type wire nuts, yellow and crumbling paper masking tape on splices, melted wires where there was nothing on the spice, and some big time butchering where all those K-Mart blue light special radio's were installed! An under dash fire is a lot harder to extinguish and if at home in your garage, then you've got an even larger safety issue.

One of my non tach Mach 1's is off the road now waiting for my money tree to mature. When I go back with the tachometer cluster, the wire harness will definitely be going to Midlife. The peace of mind you'll have knowing your "Money Pit" is not going to burn to the ground is worth the money spent!!

I completely under stand what your saying. I'm hoping and expecting the doner car is in good shape. I've owned the doner car for nearly 20 years and I personally installed the stereo and did it right. but we'll see. It has been sitting for 4 or 5 years and you never know what the mice might have been up to. But for now the tach and gauges are going low on the priority list of thing to do before power tour.

 

[Totalled]

Wear gloves. There is a shit-ton of sharp metal under the dash you are about to get up close and personal with.

 

[Carolina_Mountain_Mustangs]

Pulling the entire dash is the way to go on this job. You will go crazy trying to lay on your back and do all the work you are talking about. With the dash out you can get to all the duct work for the air cond. work and it is a breeze to get the harness out and back in. You can put every piece of the dash together on the bench before installing it. All of the harness unplugs at the bottom of the kick panels on each side and the fuse block has the one bolt in the center and that separates the under dash harness from the under hood harness.

I had to pull off working on my car to get something moving on the garage but hope to get back on it maybe next week. You can have the entire dash out in minutes not hours. Two bolts on the top of the dash one on each side near the A post. There are two bolts on each side going up through the front end of the dash. Pull the glove box and there is one wireform brace that goes from lower part of dash to the cowl. Unhook the connections for the heater/air and unplug the harness. There is one bolt that is hidden under the steering column. Drop the column first thing and it will be right in the center above the column. There is a couple wire connections you need to take loose from heater while pulling the dash out. Come out slow and look for the wires still attached. A helper is great I had to do mine by myself.

For sure you want to add a quick disconnect to your battery. When at shows you can disconnect to save the battery and I never leave it connected when in garage. Those mice can do some strange things with wires. Brother in law had chipmunks do over $800 damage to his chevy PU harness. I watched a 69 Dodge Charger burn to the ground in parking lot at Bristol Dragway because he could not get the battery unhooked. Under dash caught fire and in minutes it was gone.

I just wish someone made a wiring diagram on one big sheet that was simple that I could follow.

David