mustang cluster swap into fairmont?

[fordguy]

looking to swap a mustang cluster into my fairmont, anyone done this?

[Dean_T]

looking to swap a mustang cluster into my fairmont, anyone done this?

I've heard this has been done. I think there is a second connector which needs to be harvested from a donor vehicle. I'll have to root around in my old files to see if I copied and pasted a write up on how a guy did this.

Dean T

[paul78zephyr]

looking to swap a mustang cluster into my fairmont, anyone done this?

Yes,
I have done this and I have documented fairly well what is needed to be done. Installing a Mustang instument cluster is generally a straight forward job but a good understanding of schematics and wiring is helpful.

The first thing you need to do is decide which Mustang instrument cluster you are going to be using. All 79-86 Mustang units are generally physically similar, however the 79-82 units have different graphics/gauge colors than the 83-86 units (the 79-82 Mustang units match the 78-83 F/Z graphic style). More importantly the 79-80 Mustang units are electrically different from the 81-86 Mustang units. The F/Z IC has a single wiring connector going to the underdash harness. All 79-86 Mustang units use two connectors. The single F/Z connector is physically the same as the two Mustang connectors.

79-80 Mustang unit (note these are easily identified as they have TWO flex circuits on the rear)
If you use a 79-80 Mustang unit then the single F/Z connector can be directly plugged into one of the Mustang units sockets (the one in the center) and the wiring will be correct but the only gauges that will operate will be the fuel and oil pressure gauge. All other functions (ie dash lights, directional indicators, hi beam ind, brake warning lamp, etc, will work. However, you must also change the oil pressure sender on the engine from a ‘light’ sender to a gauge sender or you will kill the oil pressure gauge. The operation of the tach, water temp, and ammeter gauges is on the second connector and you will have to fab you own ‘mini-harness’ for these gauges. I recommend that only the tach and temp gauges be wired as these are relatively straight forward to do. You will also need to replace the temperature sender on the engine from ‘light’ sender to the correct ‘gauge’ sender or you will kill the temp gauge. The ammeter wiring is a bit difficult to integrate correctly into the existing F/Z underdash and underhood harnesses. I did it only because I was completely rewiring my entire Zephyr and making my own new harnesses, so I was able to integrate the correct ammeter circuit.

81-86 Mustang unit (uses a single flex circuit)
If you use a 81-86 Mustang unit it will require more work as you will have to move individual wires in the single F/Z connector to different locations in this connector, move other wires from this connector to the needed second connector, and will need to run new wires to both connectors. The wiring and function pinouts of the 81-86 units two connectors is completely different than the 79-80 units. Also you may need to make some wiring splices in the F/Z harness. Basically it is a somewhat complicated job (but very do-able if you really want to use a 81-86 unit).

Regardless of whether you use the 79-80 unit or the 81-86 unit you must make some minor wiring changes at the connector on your stock externally mounted alternator voltage regulator. This is because the Mustang units do not have the ALT light and the light is part of the charging circuit.

If anyone wishes I can get into more detail on the wiring, required wiring changes, and additions.

Paul

[fordguy]

Yes,
I have done this and I have documented fairly well what is needed to be done. Installing a Mustang instument cluster is generally a straight forward job but a good understanding of schematics and wiring is helpful.

The first thing you need to do is decide which Mustang instrument cluster you are going to be using. All 79-86 Mustang units are generally physically similar, however the 79-82 units have different graphics/gauge colors than the 83-86 units (the 79-82 Mustang units match the 78-83 F/Z graphic style). More importantly the 79-80 Mustang units are electrically different from the 81-86 Mustang units. The F/Z IC has a single wiring connector going to the underdash harness. All 79-86 Mustang units use two connectors. The single F/Z connector is physically the same as the two Mustang connectors.

79-80 Mustang unit (note these are easily identified as they have TWO flex circuits on the rear)
If you use a 79-80 Mustang unit then the single F/Z connector can be directly plugged into one of the Mustang units sockets (the one in the center) and the wiring will be correct but the only gauges that will operate will be the fuel and oil pressure gauge. All other functions (ie dash lights, directional indicators, hi beam ind, brake warning lamp, etc, will work. However, you must also change the oil pressure sender on the engine from a ‘light’ sender to a gauge sender or you will kill the oil pressure gauge. The operation of the tach, water temp, and ammeter gauges is on the second connector and you will have to fab you own ‘mini-harness’ for these gauges. I recommend that only the tach and temp gauges be wired as these are relatively straight forward to do. You will also need to replace the temperature sender on the engine from ‘light’ sender to the correct ‘gauge’ sender or you will kill the temp gauge. The ammeter wiring is a bit difficult to integrate correctly into the existing F/Z underdash and underhood harnesses. I did it only because I was completely rewiring my entire Zephyr and making my own new harnesses, so I was able to integrate the correct ammeter circuit.

81-86 Mustang unit (uses a single flex circuit)
If you use a 81-86 Mustang unit will reguired more work as you will have to move individual wires in the single F/Z connector to different locations in this connector, move other wires from this connector to the needed second connector, and will need to run new wires run to both connectors. The wiring and function pinouts of the 81-86 units two connectors is completely different than the 79-80 units. Also you need to make some wiring splices in the F/Z harness. Basically it is a somewhat complicated job (but very do-able if you really want to use a 81-86 unit).

Regardless of whether you use the 79-80 unit or the 81-86 unit you must make some minor wiring changes at the connector on your stock externally mounted alternator voltage regulator. This is because the Mustang units do not have the ALT light and the light is part of the charging circuit.

If anyone wishes I can get into more detail on the wiring, required wiring changes, and additions.

Paul

awesome info Paul, thanks alot!

[FuturaGuy]

looking to swap a mustang cluster into my fairmont, anyone done this?

Fordguy:

If you haven't seen it already, check your personal messages. I sent you a PM.

[fordguy]

Fordguy:

If you haven't seen it already, check your personal messages. I sent you a PM.

pm'd back, very interested!

[Chuck W]

I did the swap in my '80
http://vb.foureyedpride.com/showthread.php?t=28521

[82_4door]

I just picked up a Mustang cluster for $5.99 plus shipping on ebay! Only one picture, but i think it's the 79-80 by the graphics. It has green and white lettering on black face. So if it has 2 seperate flex circuits on the back, it's the early version? Anyone know what the redline is on a 5.0 HO? I think this tach tops at 6k, and doesn't show a redline.

[cleger]

If anyone wishes I can get into more detail on the wiring, required wiring changes, and additions.

Paul, I'll be in touch/asking in the near future. Have this cluster on the way. Not sure yet which vintage it is. Have my fingers crossed.

[FoxChassis]

I almost bid on that cluster. But I thought $40 shipped was high. I wanted it for the 8K tach (4 cyl only cars).

[cleger]

Yeah, a little pricey, what with the unknown condition and all... figured I'd take a chance. I wanted it for the green color and Km/H speedo, since my car has one already.

Argh. Is there any way I can adapt this tach for use on an 8 cyl car? This is what I get for not having any references available. I keep thinking the ones with no redline that stop at 6K are for 4/6 cyl cars. Passed one up a wile ago that was identical to this one except for the 6k tach. I'd really like to be able to take my motor past 6K and still see what's going on.

[FoxChassis]

The 6K tachs are the ONLY ones that are switchable between 4-6-8. The circuits for all three are complete.

The 8K tachs are from 2.3T cars and have one of the three circuits (4 cyl) complete. The 6 and 8 cylinder circuits are imcomplete. If you can figure out what resistors are required to complete the circuit(s) you want, the 8K tach will work with a 6 or 8 cylinder.

[cleger]

OK. Shouldn't be too hard then. I think I'll be able to figure it out.

Just need to either get my hands on one of the switchable ones, or else a schematic.
Thanks!

[paul78zephyr]

Paul, I'll be in touch/asking in the near future.

Start here:
http://vb.foureyedpride.com/showthread.php?t=42881


Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[cleger]

Thanks Paul! I've filed your instructions. Fingers still crossed re: which type of pod I have coming.

[Fearmont]

Paul, I'll be in touch/asking in the near future. Have this cluster on the way. Not sure yet which vintage it is. Have my fingers crossed.

Maybe when you get your's done I'll drive up and you can help me!!!lol

Phillip

http://cgi.ebay.com/ebaymotors/ws/eB...m=150139712637

[cleger]

Cluster arrived, and I finally got around to playing with it.

First of all, when I first looked at it, it seemed as if the face of the tach had been cleaned using a screwdriver. Turned out that it had some minor scratches in combination with some crap smeared on it, apparently in the same "operation." Also, the housing was shattered at the bottom, but it's mostly there and I glued it back together, and covered the holes with duct tape for now to keep the panel lights from bleeding all over the place.

A little judicious cleaning and polishing of the face and it looks quite good, albeit a bit glossier than it is probably supposed to be, but very presentable. With the fist connector plugged in (and water temp and oil pressure senders disconnected) the speedo and gas gauges both work, as do the panel lights and high beam indicator. Turn signal indicators don't work though, even though both bulbs are good. I'll ahve to look a little further on that, I suppose.

Question for you, Paul; in your text file (thanks!) you write that the ammeter connections are on connector C217 at #s 13 and 14. What are these terminals connected to, once the changes are made at the regulator? I'm probably missing something, but I've read the file several times and I can't figure it out.

I'm assuming part of the ammeter circuit comes in on C202, since that's where the idiot light wiring is in the Fairmont harness?

Thanks!

[paul78zephyr]

With the fist connector plugged in (and water temp and oil pressure senders disconnected) the speedo and gas gauges both work, as do the panel lights and high beam indicator. Turn signal indicators don't work though, even though both bulbs are good. I'll ahve to look a little further on that, I suppose.

Im assuming you are sure you have a 79/80 Mustang cluster (with TWO flex circuits) - you never really said what you were getting?

Speedo is non-electric so has nothing to do with wiring. Do the turn signal lamps on the front and rear of the car work, just not the dash indicators?

Question for you, Paul; in your text file (thanks!) you write that the ammeter connections are on connector C217 at #s 13 and 14. What are these terminals connected to, once the changes are made at the regulator? I'm probably missing something, but I've read the file several times and I can't figure it out.

I'm assuming part of the ammeter circuit comes in on C202, since that's where the idiot light wiring is in the Fairmont harness?

Terminals 13 and 14 (on a 79/80 Mustang cluster) go to splices on the 'main' power supply wire (circuit 37) coming from the started solenoid +Bat terminal and going to the ignition switch and fuse box to form what is called a 'shunt'. The location of those splices and the size of the wires going to the meter are critical to making the ammeter operate properly. The circuit 37 wire and the spliced in shunt wires to the ammeter are part of the underhood harness. Ill look to see if I can find a good schematic that shows the shunt.

The ammeter wires are only on C217. Actually the operation of the ammeter has nothing to do with charging circuit and as I have said in my writeup you could simply choose not to use them. The reason you need to make wiring changes at the voltage regulator is not because you are adding the ammeter, but because you are deleteing the charge indicator lamp which is part of the circuit. The wire that used to go to the lamp is on C202 and goes to the voltage regulator.


Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[cleger]

Im assuming you are sure you have a 79/80 Mustang cluster (with TWO flex circuits) - you never really said what you were getting?

Sorry... right, it turned out to be a 1980 cluster. 2 flex circuits, etc.

Speedo is non-electric so has nothing to do with wiring. Do the turn signal lamps on the front and rear of the car work, just not the dash indicators?

signals on the car work, but not in the cluster.

Terminals 13 and 14 (on a 79/80 Mustang cluster) go to splices on the 'main' power supply wire (circuit 37) coming from the started solenoid +Bat terminal and going to the ignition switch and fuse box to form what is called a 'shunt'. The location of those splices and the size of the wires going to the meter are critical to making the ammeter operate properly. The circuit 37 wire and the spliced in shunt wires to the ammeter are part of the underhood harness. Ill look to see if I can find a good schematic that shows the shunt.

The ammeter wires are only on C217. Actually the operation of the ammeter has nothing to do with charging circuit and as I have said in my writeup you could simply choose not to use them. The reason you need to make wiring changes at the voltage regulator is not because you are adding the ammeter, but because you are deleteing the charge indicator lamp which is part of the circuit. The wire that used to go to the lamp is on C202 and goes to the voltage regulator.


Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

Ah, ok, I see. I may just take your advice and ignore the ammeter.

Reminds me of a '72 LTD I had many years ago (still miss that car) that suddenly started blowing regulators. I was literally buying them 3 at a time. (20+ years ago. I think they were about $10 ea at the time)

Late one night, many regulators later, I was out on the highway miles from home and the idiot light started flickering. I realised with horror that I was out of regulators (!!! no cell phones in those days) so I pulled the car over, reached up and pulled the bulb out of the cluster. It was a case of just not wanting to know. I drove off, thinking the car would die any minute, but it ran for a couple more years on that regulator! Probably should have changed it, but never did.

Thanks Paul!

[paul78zephyr]

Sorry... right, it turned out to be a 1980 cluster. 2 flex circuits, etc.

signals on the car work, but not in the cluster.

Well that is wierd as you said you have checked the bulbs. And you say that the indicators worked on you old cluster - for sure? It cant be the ground as the turn signal indicators share the same ground with the h-beam ind and the illumination lamps - and you said they work. Are you sure both lamp holders are making good contact with the flex circuit?

Ah, ok, I see. I may just take your advice and ignore the ammeter.

Reminds me of a '72 LTD I had many years ago (still miss that car) that suddenly started blowing regulators. I was literally buying them 3 at a time. (20+ years ago. I think they were about $10 ea at the time)

Late one night, many regulators later, I was out on the highway miles from home and the idiot light started flickering. I realised with horror that I was out of regulators (!!! no cell phones in those days) so I pulled the car over, reached up and pulled the bulb out of the cluster. It was a case of just not wanting to know. I drove off, thinking the car would die any minute, but it ran for a couple more years on that regulator! Probably should have changed it, but never did.

Thanks Paul!

You can always go back and wire up the ammeter later. Try to get the rest of the gauges squared away. Do you have a 'second' connector (plastic housing and contacts) for the tach and water temp gauge connections on C217? You will need 4 contacts (3 for tach and one for temp). When you get to the ammeter you will need 2 more.

The charge indicator light is controlled by the regulator, however just because the light is on with the engine running does not mean you have a bad regulator. The regulator acts like a 'switch' between the charge indicator light and the ignition switch. With the key on and engine off the 'switch' is closed and the light is on. When the engine starts the alternator makes volatge which the regualtor senses and the 'switch' is opened and the light goes out. Anything that causes the alternator to have little or no output - bad alternator, bad regulator, bad wiring, even a loose fan belt - will cause a low/no-voltage and the light will come on / stay on / flicker.


Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[cleger]

Well that is wierd as you said you have checked the bulbs. And you say that the indicators worked on you old cluster - for sure? It cant be the ground as the turn signal indicators share the same ground with the h-beam ind and the illumination lamps - and you said they work. Are you sure both lamp holders are making good contact with the flex circuit?

I'm not sure. I just stuck it in the dash to test it yesterday. Speedo, fuel gauge and high beam indicator worked, so I pulled it back out for about 3 hours' worth of cleaning/polishing/gluing/taping. I had pulled alll the bulbs to eyeball the filaments... maybe the bulbs are bad after all. I have plenty of good ones in the old cluster to swap in, and the turn indicators did work in the old cluster.

You can always go back and wire up the ammeter later. Try to get the rest of the gauges squared away. Do you have a 'second' connector (plastic housing and contacts) for the tach and water temp gauge connections on C217? You will need 4 contacts (3 for tach and one for temp). When you get to the ammeter you will need 2 more.

I don't have an extra connector, but I'll either find one or rig something up in the short-term.

The charge indicator light is controlled by the regulator, however just because the light is on with the engine running does not mean you have a bad regulator. The regulator acts like a 'switch' between the charge indicator light and the ignition switch. With the key on and engine off the 'switch' is closed and the light is on. When the engine starts the alternator makes volatge which the regualtor senses and the 'switch' is opened and the light goes out. Anything that causes the alternator to have little or no output - bad alternator, bad regulator, bad wiring, even a loose fan belt - will cause a low/no-voltage and the light will come on / stay on / flicker.


Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

In my case, the LTD was burning regulators. I chased that problem for a while. Car was burning a regulator every couple hundred miles. The light would eventually start flickering, and shortly thereafter the headlights and other lights would start dimming, and the car would not re-start. I can't remember what it did to the charge state of the battery, but remove the regulator, and the little coil on the base of it would be burned black. One time I even tried one of those (expensive) "solid state" aluminum heat-sinked regulators, with similar result.

Went so far as to take it to my father's mechanic... he kept it for a couple of days and couldn't figure it out, except that there was a short somewhere. (No charge. Those were the days.)

Seriously miss that car. 429 4v was smooth, quiet and fast. Got hit in it twice - $thousands to the other car in both cases, in my case one of the hits took a half-inch chunk out of one of the rubber strips on a rear over-rider, but that was it. I remember sitting at the light, feeling a slight bump, thinking "what was that?" looking in the mirror to see a hood bent up in the air and coolant spewing. Opened the door, and the woman was already getting out of her Honda, crying "oh my God, I'm so sorry..." finally got her calmed down when I pointed out that I had paid $250 for my car, and that there was no real damage to it. Then her tune changed to "my husband is going to kill me."

Second time was similar, except it was a guy in a Malibu wagon, who hit the brakes hard enough to get his front bumper under my rear one, which took out his whole nose, hood, etc. "Sorry, sorry, sorry," but again, no damage to my car.

Then there was the time, late one night, when my wife and I emerged from that revolving restaurant in the Cambridge Hyatt to find we'd been blocked in by an inconsiderate VW Jetta driver... that was the event that convinced me to keep the LTD, which I'd originally bought as a "winter" car.

Sorry to reminisce! This probably belongs in "General BS."

[paul78zephyr]

I had pulled alll the bulbs to eyeball the filaments... maybe the bulbs are bad after all. I have plenty of good ones in the old cluster to swap in, and the turn indicators did work in the old cluster.

Recheck/replace all the bulbs

I don't have an extra connector, but I'll either find one or rig something up in the short-term.

Remember that the connectors are the same so you can get one from any 78-83 F/Z, 79-86 M/C, 81-82 G/C, and Im pretty sure 83-86 L/M. Maybe other Fords too. When you get the connecter just be sure to leave a few inches of wire on the terminals to solder a new wire to.

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[cleger]

Thanks again Paul.

Turns out the turn signal issue was not as I described... noting was working because I bonked the column switch removing the shroud to get at the dash. No aspect of the signals were working. I just assumed the outside lamps were since they were working right up until I installed the cluster.

Recheck/replace all the bulbs

Remember that the connectors are the same so you can get one from any 78-83 F/Z, 79-86 M/C, 81-82 G/C, and Im pretty sure 83-86 L/M. Maybe other Fords too. When you get the connecter just be sure to leave a few inches of wire on the terminals to solder a new wire to.

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

D'oh. I am such an idiot. I was at Menard's TODAY and it never occured to me to ask about a connector. Forgot a couple of other things too. Looks like I need to make another trip. Too many things going on.

Thanks again, Paul!

[paul78zephyr]

So the turn signal indicators work OK?

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[cleger]

So the turn signal indicators work OK?

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

Yup, they work fine. The upper RH panel lamp is out though, so need to go back in after that. Also, the gas gauge reads low, so I'll need to carefully tweak the needle a bit. Put the cluster in with a quarter tank of gas, and it read near empty. Filled it today, and the needle stopped at 7/8 of a tank.

Foxchassis is right, there's nothing but a hole and some empty solder pads where the 4-6-8 selector is supposed to be. No luck getting my hands on a broken one at Menard's today. Anyone happen to have a tach laying around that they can see the resistors on the board around the selector? All I'd need is a description of the colored stripes on them. Either that, or I have a feeling I'm going to end up buying a good one on ebay in order to fix mine.

Panel looks very cool, I have to say. Covered it with an all-black '82 (I think) turbo bezel. Green gauges look great.