Adding 1966-style gauges to a 1965 Mustang

[stephanorf]

Has anyone converted their 1965-style gauge cluster to the 1966 gauges?

Here's what I have done so far, and I have run into a little snag:

Purchased:

1966 under dash harness
1965 Alternator harness with gauges
1965 Headlamp harness with gauges
1966 Gauge feed harness
1966 Gauge Cluster

================================================== =========

Under dash loom

Underdash, everything is connected and there is only 1 wire that doesn't have a home. Here's the thread for that wire: 1966 Mystery Solod White Wire

================================================== ==========

Gauge Feed Harness

At the Solenoid, there is 1 wire that I think is supposed to connect to the headlamp harness, but the 1965 headlamp harness doesn't have the connection. Here's the thread for that wire: Another wire without a home

================================================== ==========

Alternator Harness: 1965 with gauges VS 1966

Then there is the alternator harness. There is a Alt harness for 1965 with gauges, and there is an alternator harness for 1966. Since there are two harnesses, you would think there would be some difference between the two. They both look exactly the same and have the same number of wires, and even the wire colors are the same. Check it out.

Here's a 1965-with-gauges alternator harness:



and here is the 1966 alt harness:



I don't see a difference, but there must be one since there is a different harness for each year. Does anyone know what the difference between the two harnesses is?

================================================== ==========

1965 to 1966 gauge conversion Lessons Learned

Also, has anyone done this conversion? Please post any comments/suggestions/learnings you would like to share. This is my first conversion and it isn't as straight-forward as I had hoped it would be!

Thanks!

[ivygreen65]

Your picture of the 65 alternator harness doesn't look correct. The 65 harness should have a female plug for the radio suppressor. The 66 harness won't have the female plug because the 66 alternator had an internal radio suppressor.

[09Frank65]

Originally Posted by ivygreen65

Your picture of the 65 alternator harness doesn't look correct. The 65 harness should have a female plug for the radio suppressor. The 66 harness won't have the female plug because the 66 alternator had an internal radio suppressor.

Alternator harness with gauges is different than standard 65.

[dzahm]

Installing 66 Gages in a 65

This is the website I was using in prep to do the same thing. I hope this is not against any rule- if so pls delete- If not hope it helps

[JamesWnew]

Originally Posted by dzahm

Installing 66 Gages in a 65

This is the website I was using in prep to do the same thing. I hope this is not against any rule- if so pls delete- If not hope it helps

Not against the rules. I did this webpage almost 10 years ago now. Car hasn't burnt up and alt works so I guess it's ok.

A couple of small but very convenient steps at this point are:
- use connectors to make the dash a quick disconnect and
- make all the wires long enough to pull out as a harness and sit aside while troubleshooting.

[bartl]

Originally Posted by stephanorf

Has anyone converted their 1965-style gauge cluster to the 1966 gauges?

Here's what I have done so far, and I have run into a little snag:

Purchased:

1966 under dash harness
1965 Alternator harness with gauges
1965 Headlamp harness with gauges
1966 Gauge feed harness
1966 Gauge Cluster

================================================== =========

Under dash loom

Underdash, everything is connected and there is only 1 wire that doesn't have a home. Here's the thread for that wire: 1966 Mystery Solod White Wire

I looked at the thread... it looks like you can see a white wire on the back side of the fuse box. Have you put an ohmmeter on the wire and probed some different feeds/leads to see if you get continuity with any?
================================================== ==========

Gauge Feed Harness

At the Solenoid, there is 1 wire that I think is supposed to connect to the headlamp harness, but the 1965 headlamp harness doesn't have the connection. Here's the thread for that wire: Another wire without a home

All my diagrams show that wire connecting to the A+ terminal on the voltage regulator. Trace back the wiring from the regulator plug to see where the A+ lead goes.
================================================== ==========

Alternator Harness: 1965 with gauges VS 1966

Then there is the alternator harness. There is a Alt harness for 1965 with gauges, and there is an alternator harness for 1966. Since there are two harnesses, you would think there would be some difference between the two. They both look exactly the same and have the same number of wires, and even the wire colors are the same. Check it out.


I don't see a difference, but there must be one since there is a different harness for each year. Does anyone know what the difference between the two harnesses is?

It looks like the major difference is the way the wires are wrapped...one uses the cloth type wrap, the other doesn't...
================================================== ==========

1965 to 1966 gauge conversion Lessons Learned

Also, has anyone done this conversion? Please post any comments/suggestions/learnings you would like to share. This is my first conversion and it isn't as straight-forward as I had hoped it would be!

Thanks!

HTH

[stephanorf]

Originally Posted by JamesWnew

Not against the rules. I did this webpage almost 10 years ago now. Car hasn't burnt up and alt works so I guess it's ok.

A couple of small but very convenient steps at this point are:
- use connectors to make the dash a quick disconnect and
- make all the wires long enough to pull out as a harness and sit aside while troubleshooting.

Nice website. Cool mods. Great looking car. Good job!

[stephanorf]

Originally Posted by bartl

Originally Posted by stephanorf View Post
Has anyone converted their 1965-style gauge cluster to the 1966 gauges?

Here's what I have done so far, and I have run into a little snag:

Purchased:

1966 under dash harness
1965 Alternator harness with gauges
1965 Headlamp harness with gauges
1966 Gauge feed harness
1966 Gauge Cluster

================================================== =========

Under dash loom

Underdash, everything is connected and there is only 1 wire that doesn't have a home. Here's the thread for that wire: 1966 Mystery Solod White Wire

I looked at the thread... it looks like you can see a white wire on the back side of the fuse box. Have you put an ohmmeter on the wire and probed some different feeds/leads to see if you get continuity with any?

I did check for continuity on the white wire to the fuse box. The white wire is attached to the "14A ACCY" fuse. Evidently this is some specific purpose accessory for 1966 Mustangs. If anyone has a 1966 Mustang, it sure would be nice to know what is plugged into the white accessory wire that comes out of the main harness near the fuse box. I was wondering if maybe it could be for the air conditioner (mine is a fused lead that goes to the back of the ignition switch). What other accessory would be so common as to entitle it to its own special wire?
================================================== ==========

Gauge Feed Harness

At the Solenoid, there is 1 wire that I think is supposed to connect to the headlamp harness, but the 1965 headlamp harness doesn't have the connection. Here's the thread for that wire: Another wire without a home

All my diagrams show that wire connecting to the A+ terminal on the voltage regulator. Trace back the wiring from the regulator plug to see where the A+ lead goes. The yellow lead on the 1966 headlamp harness probably comes from the voltage regulator. I don't have a 1966 headlamp harness to test, but when I get one I will.

After looking at the 1966 headlight harness, it is a direct match for the 1966 gauge feed harness. The 1966 headlamp harness has a yellow wire with a male bullet connector that terminates at the solenoid. That yellow wire is the mate to the yellow wire that is so lonely and empty as pictured in the original thread.

================================================== ==========

Alternator Harness: 1965 with gauges VS 1966

Then there is the alternator harness. There is a Alt harness for 1965 with gauges, and there is an alternator harness for 1966. Since there are two harnesses, you would think there would be some difference between the two. They both look exactly the same and have the same number of wires, and even the wire colors are the same. Check it out.


I don't see a difference, but there must be one since there is a different harness for each year. Does anyone know what the difference between the two harnesses is?

It looks like the major difference is the way the wires are wrapped...one uses the cloth type wrap, the other doesn't...

I wonder why they make two different harnesses. It seems it would be a lot more economical to just offer one harness if they are identical. I suppose the type of wrap makes a difference though...especially if it is supposed to be "correct". I have the 1965-with-gauges harness and it is wrapped with shiny black plastic (not cloth). Is it the 1966 that is supposed to use the cloth wrap?

================================================== ==========

1965 to 1966 gauge conversion Lessons Learned

Also, has anyone done this conversion? Please post any comments/suggestions/learnings you would like to share. This is my first conversion and it isn't as straight-forward as I had hoped it would be!

Thanks!

Thanks!