Gauge Cluster Upgrade

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vintageracer
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Gauge Cluster Upgrade

Post by vintageracer »

I have searched the forum and have not had any luck finding an answer to my question so here it goes:

I have a 66 Monza 4 Speed A/C equipped 2 door with extra doors (4 Door) Corvair.

I have a tele column to install and would like to also install a full gauge instrument cluster from a Corsa parts car a friend of mine owns. He tells me that will have to change the complete wiring harness in the car. I understand and expect to have to change out the"dash main" harness with the "dash main" harness from the Corsa parts car that matches the full gauge cluster

Therefore my questions:

Must I also change the rear harness and front harness in the car to make this gauge cluster upgrade?
Mike

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terribleted
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Re: Gauge Cluster Upgrade

Post by terribleted »

You do not really have to do all that. You will want the corsa instrument cluster harness (you could do some splicing of you current cluster harness to get all the dash light working if need be. If you want the tach to work you will need to run a wire to it from the coil. If you want the manifold pressure gauge (will show vacuum in your configuration) you will need to run the small plastic vacuum (boost) line from the engine to the gauge. You can use a 140 or ideally a turbo vacuum balance pipe instead of your stock one to supply the original fittings at the engine end, but, you could simply adapt the line to the unused left carb vacuum port or into your stock balance tube or find a way to T it into your current vacuum balance tube. As I recall the rest of the functions in your dash harness where it plugs into the cluster harness are the same as your current wiring so everything else should function just fine.

So essentially you need only the gauge cluster harness that hopefully is with the used CORSA gauges and to run one wire from coil to tach and run the vacuum tube.
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martyscarr
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Re: Gauge Cluster Upgrade

Post by martyscarr »

Must I also change the rear harness and front harness in the car to make this gauge cluster upgrade?
Instead of changing the wiring harnesses, you can just add the additional required wires. You can purchase the correct wire connectors from Clark's to fit into the molded plugs and make it look factory. You need a tachometer wire, a wire for the thermistor (if you're going to add one). and some power for the clock which you can get at the fuse block.

Here's a nice wiring diagram in color that should help: http://www.rament.net/corvair/1965_corv ... ematic.jpg

HTH
Marty Scarr
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terribleted
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Re: Gauge Cluster Upgrade

Post by terribleted »

martyscarr wrote: Sun Nov 26, 2017 6:38 pm
Must I also change the rear harness and front harness in the car to make this gauge cluster upgrade?
Instead of changing the wiring harnesses, you can just add the additional required wires. You can purchase the correct wire connectors from Clark's to fit into the molded plugs and make it look factory. You need a tachometer wire, a wire for the thermistor (if you're going to add one). and some power for the clock which you can get at the fuse block.

Here's a nice wiring diagram in color that should help: http://www.rament.net/corvair/1965_corv ... ematic.jpg

HTH
Marty Scarr
LOL oh yeah clock power feed and thermistor wire...2 more wires to add in addition to above (not sure you actually need to add a wire for the clock it might already be present as Monzas could get clocks as well). Still not a big deal. (of course you would need to install a thermistor in the left head for the temp gauge to work. Clark's sells an adapter to do this (you supply thermistor).
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
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66vairguy
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Re: Gauge Cluster Upgrade

Post by 66vairguy »

I've done a few of these -- You don't have to use the Corsa engine harness. The 65 cars used a "buzzer" with the over temp switch, but not the oil pressure switch requiring two wires in the engine compartment all the way to the dash harness. It's not an issue since the "buzzer" was dropped in 66 so the Monza wiring works fine. I just brought it up for the purist who want to add the 65 only "buzzer" or those who say you have to have the Corsa engine harness.

You don't have to change the "tunnel" harness. You will have to bring a wire to the front for the tachometer and thermistor (drives the temperature gauge) via the "tunnel" harness and keep in mind the throttle linkage and emergency brake cable moves in this area so you have to keep the wires secured in a good location. Other's mention the vacuum gauge tubing, but you need the proper vacuum cross over tube to hook it up - Clark's sells the tubing

You did not say what engine you have. Thermistors were only used on the 140HP and Turbo cars. At some point in the future there may be a modern replacement to fit the non-140/turbo heads and drive the gauge.

The Monza clock was an option and included a SEPARATE wire that plugged into the fuse box. The Corsa clock power came in via the Corsa harness to the instrument cluster plug. You can add that wire from the fuse box to the Corsa instrument cluster plug, if you have terminals that require a special crimp tool (forget using pliers). Of course the old clocks usually have to be upgraded to a quartz movement to work reliably.

BTW - DO NOT WASTE YOUR TIME AND EFFORT cobbling up a Monza instrument harness to use on a Corsa instrument cluster. A lot of used Corsa clusters come with the harness, or you can buy a new one from Clark's.

OR --- another thought is to add a new tachometer to the center (was for optional Monza clock) Monza cluster spot. It's a nice upgrade done by a few and you don't have to worry about a temp gauge that doesn't work due to no thermistor, or a vacuum/boost gauge not hooked up (and useless on the non-turbo engine), or fixing a clock. Search the Corvair Center forum for Monza tachometer adds - some nice ones there.

Keeping the Monza A/C dash also means you don't have to cut a hole in the Corsa instrument cluster for the A/C vent (I've done two, not a big deal, just one more thing).

Just my 2cents.
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bbodie52
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Re: Gauge Cluster Upgrade

Post by bbodie52 »

I have grabbed a portion of the overall Corsa and Monza wiring schematics to show the instrument cluster wiring detail for each one side-by-side. In the illustration below you will see that the 12 pin multi-connector for the Monza instrument cluster is less-densely populated with wiring connections than the 12 pin multi-connector for the Corsa instrument cluster. If you focus on the areas that are highlighted in gray you will see that the left half of the 12 pin multi-connector for the Corsa and Monza wiring harness is the same. Only the right half differs with some omissions on the left side of the 12 pin plug. The Corsa plug has a tachometer connection on the second pin from the top and the cylinder head temperature gauge connection on the third pin from the top. The last pin on the bottom left is the power feed for the clock. The differences on the left side of the connector (which would be incorporated in the wiring harness that is a part of the Corsa instrument panel) support the tachometer, cylinder head temperature gauge, and clock. The manifold vacuum/pressure gauge is a mechanical gauge that is connected by a nylon (plastic) vacuum tube that connects to the Corsa vacuum balance tube in the engine compartment. The Monza vacuum balance tube would not have the needed connection point for the vacuum tube. Without a turbocharger the gauge is not all that useful. There is no electrical connection for that gauge. The speedometer is also a mechanical gauge that connects in the same way on both the Corsa and the Monza. The fuel gauge is electrically the same for both the Corsa and the Monza. Tachometer power in the Corsa instrument panel is simply tapped at a junction point within the Corsa instrument panel wiring harness. So the wiring differences in the Corsa instrument panel are mostly handled by the dedicated Corsa instrument panel wiring harness.

The wiring schematics in the 1965 Corvair Chassis Shop Manual do not show a reduction in the wiring on the left side connector. You would have to examine the actual connector within the Monza dashboard to see if any of those wires that are needed by the Corsa instrument panel actually exist in the Monza wiring harness. If the power feed for the clock and the sensor wires for the tachometer and cylinder head temperature gauge are simply empty holes in the Monza connector, you would have to add those wires to connect to the negative side of the ignition coil (tachometer sensor). There would be no thermistor in the left cylinder head of the Monza engine to link to the cylinder head temperature gauge. If you want that gauge to work you would have to obtain a thermistor (difficult to find) and probably an adapter to fit it to the left cylinder head, and add the wire as well. It is unlikely that the electromechanical clock in the Corsa instrument panel is actually functional. Most of them have failed long ago. There is a conversion kit to install an electronic clock (often found on eBay) that makes use of the face and hands of the old Corsa clock if you wish to make that modification to the Corsa instrument panel. If you do, a power wire would have to be added to support the electronic clock.

Left-click the image to enlarge it for better viewing or "Pan & Scan"...
Corsa vs Monza Instrument Panel Wiring Comparison.jpg
The full Corsa and Monza wiring schematics and be seen by clicking on the following link. The schematics are for a 1965 Corvair. The 1966 wiring harness would be very similar, but some of the color codes for the wires may have changed in 1966.

CORVAIR COMBINED WIRING SCHEMATIC DIAGRAMS
:link: viewtopic.php?f=225&t=12968
Brad Bodie
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azdave
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Re: Gauge Cluster Upgrade

Post by azdave »

66vairguy wrote: Sun Nov 26, 2017 8:02 pmThe 65 cars used a "buzzer" with the over temp switch, but not the oil pressure switch requiring two wires in the engine compartment all the way to the dash harness. It's not an issue since the "buzzer" was dropped in 66 so the Monza wiring works fine. I just brought it up for the purist who want to add the 65 only "buzzer" or those who say you have to have the Corsa engine harness.
More to the point about the over-temp buzzer on late models...that feature was only installed on the turbo Corsas. The 140 Corsas had the wiring and plug in place but no buzzer was installed. Other than the Corsas, no late model Corvairs had that wiring or plug pre-installed.
Dave W. from Gilbert, AZ

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rfw66
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Re: Gauge Cluster Upgrade

Post by rfw66 »

If you are up for something a little different, Tom Knoblauch sells a gauge retainer, for aftermarket gauges for your Monza cluster. You purchase modern gauges, with any face you like and the GPS speedometers need no calibration!
You might drop Tom a note to get more info and pricing!
I am in process of changing my ‘68 Monza dash to new, modern gauges.
Seth Emerson sells gauge retainers for the Corsa dash cluster for modern gauges too



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Bob W
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