Instrument Cluster interchangeability!!!

[Fordman]

Anybody know if the Instrument Clusters are interchangeable between all 79-86 models with the SVO clusters? Is the printed circuit board the same. I know the Speedometer is different and the Boost Gauge is there in place of what an Ampmeter. The reason I ask is that I was going to try and swap one in to mine to see if it fixes my problem w/ my gauges and I just got outbid on ebay by someone named low86GT. Hope they are putting it in an SVO. Anyway he bid $80 and got it. I know I could get a non-SVO cluster for a lot less.

BTW: What makes changes the Speedometer to read on a 140 mph speedometer? Does it have a different Sending Unit than GTs and LXs. My Speedometer reads consistently 5 mph too low and it bounces sometimes.

[SVOBart]

My EVTM shows no difference in the wiring apart from the missing ammeter in the SVO cluster. I wouldn't be suprised if the wire needed to make the ammeter work is even in the SVO harness. Try it out and report back to us if it works. Just make sure to turn the cylinder selector to 4 if you pull the cluster out of a 6 or 8 cylinder car. Otherwise the tachometer will read low, if at all.

Speedometer calibration is done in the speedo head itself, so feel free to swap in a 85 mph speedometer just to check for proper operation.

[Fordman]

Originally posted by SVOBart
My EVTM

Whats EVTM?

Originally posted by SVOBart
Speedometer calibration is done in the speedo head itself, so feel free to swap in a 85 mph speedometer just to check for proper operation.

So your saying that the Sensor in the side of the Transmission is the same as any other Mustang that has the same Axle Ratio, but the head inside the Speedometer on the Cluster is SVO Specific? Is electronic or mechanical with gears?

[boostedbruiser]

From EXPERIENCE, the cluster physically will fit but you have to use the red SVO powerwiring on the back of the cluster or the car won't charge. its part of the circut, ask me how i know. lol

[SVOBart]

An EVTM stands for Electrical-Vaccum Troubleshooting Manual. If you don't have one of these for your car, get one. It is the Ford factory manual that has the wiring and vaccum diagrams for the entire car, broken down by EEC, lighting, power accessories, charging, etc.

Our cars use a gear driven speedometer. Both the drive and driven gear can be swapped out to compensate for swapping the rear axle gears or for extreme changes in tire diameter. So yes, the white gear used on SVOs with a 3.73:1 rear axle is exactly the same as any other Ford car or truck that had the same axle ratio. Keep in mind that no other Fox Mustang ever came with 3.73:1 gears. N/A 4 cylinder cars only got as steep as 3.45:1 I beleive.

[Pat_in_L.A.]

Originally posted by boostedbruiser
From EXPERIENCE, the cluster physically will fit but you have to use the red SVO powerwiring on the back of the cluster or the car won't charge. its part of the circut, ask me how i know. lol

Thank you for validating what I have seen by laying the green 84 and red 85-86 side by side. The charging circuit did not look like it would complete the field wire connection.

Fordman, contact Paul Becker at SVPU. After he digs out the clusters in storage that I ordered, I think that he can beat that 80 buck price.

[Erics SVO]

Originally posted by Pat_in_L.A.
Thank you for validating what I have seen by laying the green 84 and red 85-86 side by side. The charging circuit did not look like it would complete the field wire connection.

Hey, maybe there is something to the fact my old 84 wouldn't start. ROB/ERIC remember that cluster was from a regular 86 4cyl! I was gonna put an aftermarket boost gauge.

-Eric

[Fordman]

Originally posted by Pat_in_L.A.
Thank you for validating what I have seen by laying the green 84 and red 85-86 side by side. The charging circuit did not look like it would complete the field wire connection.

I don't understand. Are you talking about the printed circuit on the back of the cluster. My gauges flucuate quite a bit. Especially the Fuel Gauge. The printed circuit board is separated a little and I don't know what else may be wrong with it. I was thinking I may need another circuit board and I thought I may toss in another cluster and see if they start reading accurately. Now I'm thinking I may be chasing the wrong rabbit.

Where can I get a EVTM? I definetaly need one of those.

[NavySVO]

Originally posted by MikeFleming
[url]and there are others.

Dvogelauto@aol.com, or

Douglas Vogel
4779 Meadowlark Ln.
P.O.Box 335
Dexter, Michigan 48130

[boostedbruiser]

Yes after a dead battery and 2 days of spark chasing, trying to figure out why the car wouldn't charge i looked at the printed circut wiring. the required item is that little connecting bar on the back of the cluster and some kind of light bulb, etc...... to complete the circut.

Talk about being pissed that week. i replaced the factory boost gaue location with my fuel pressure gauge, but i didn't want to hack up the old cluster.

So end result is old cluster housing new gauge installed old SVO printed circut for charging. NOW ALL GOOD.