Instrument cluster lighting

[MonzaMike]

I recently acquired a 1963 Monza Club Coupe. It has 44,500 miles on it. We (actually Mark Pannell in Claremont, NC) just went thru the car front to back. I put on new tires, some steering components, adjusted brakes, new wheel cylinders in rear, new side axle seals, new pushrod tube seals, new pan gaskets, fixed some vacuum leaks, partially rebuilt carbs, new plugs and plug wires, temp sensor, new oil cooler gaskets, new coil, and new dual exhaust. Probably a couple things I’m forgetting.
I took it for a drive yesterday and it got dark before I got home. I turned on the lights. The lights work fine; headlights, brake lights and turn signals. However, most of my instrument cluster was dark. The turn signal indicators flash green as normal. The high beam indicator comes on (red) as I activate high beams. The speedo, gas gauge and shift/gear indicator remain dark. I messed with the light switch a little. Turned it back and forth. No change. If I turn it all the way counter clockwise past the “click”, the dome light comes on.
I’ve read many posts here about cluster lamps and wiring. None that I found are quite like my issue. I’ve read BBODIE52’s very detailed reply’s to several posts. I’m mildly mechanical (changed my coil. Replaced my PCV valve and hoses, etc) but none of my basic knowledge is in electrical components. I can’t really make heads or tails out of the wiring diagrams! If I’m reading them right at all, it appears that there are 3 bulbs responsible for the darkness I’m seeing. I suppose they could all be bad but I would think odds are it’s something else. Any guidance would be much appreciated. Thanks

[Frank DuVal]

You could have several out. When looking up under the dash, the sockets (metal) with gray wire going into them are the dash illumination lamps. Pop one out and see if it is bad. Not all (OK, none) are easy to reach, but give it a try. Bad can be checked with an ohmmeter (infinity [anything over 20 ohms or so] or OL means bad), 2 jumper wires to the battery, black inside the lamp, or??? Dash lamps are #1816.

[m37aswell]

While you are at it replace all of those incandescent lamps with LED bulbs, gives a much brighter and softer light, looks great.

[bbodie52]

1964 Fuse Block and Fuse List

PANEL LPS.

• Instrument Panel Lamp
• Radio Panel Lamp
• Heater Control Panel Lamp-3AG/AGC-3 Amp

According to the 1962-1963 Shop Manual Supplement, there is a single fuse in the fuse block that feeds voltage to all of the above instrument bulbs. Power to this fuse comes from the light switch wire labeled 18V (a thin 18 Gauge wire with a Violet color). After passing through the fuse block fuse (a 2 Amp fuse labeled "PANEL LPS.") it exits the fuse block via a wire labeled 18GY (18 Gauge Gray). That wire in the wiring schematic can be traced to a wiring harness junction point, where it is distributed to each of the illumination bulbs that illuminate the instrument panel display, the radio display, the automatic transmission gear selector, and the heater controls.



Part number C1330: 60-63 HEADLIGHT SWITCH


All of these illumination bulbs have a need to be grounded properly, and all have a common voltage source (the main light switch which includes a dimmer control).

Possible sources of a common fault could be a bad light switch with a faulty internal connection or a loose/corroded or damaged wiring harness plug connector. If the voltage is actually coming out of the light switch and is reaching the fuse block, a blown fuse ia a possibility. A bad wiring harness junction point is also a remote possibility. A bad ground is unlikely, since the various bulbs in the radio, instrument panel, heater control and shift lever are all physically separate units at a variety of different attachment points (chassis grounding points) around the dashboard. If none of these bulbs on the list illuminate, the fault is probably the common source of power... i.e. the light switch, a faulty/loose harness connector plug, or a bad fuse. A voltmeter will likely show you where the fault is so it can be corrected.

I would start with checking the fuse. An inexpensive multimeter is useful for testing fuse continuity (as an ohm meter) and can also tell you if voltage is present at the fuse terminal when you turn the light switch on. Without a multimeter, you are essentially blind in that you cannot test for voltage at different connection points. If you will take the time to learn the basic operation of a multimeter and how to trace the point to point wiring depicted in the wiring schematic diagrams you can quickly open up a world of understanding that is needed to troubleshoot and test your vehicle wiring. Without it you are "blind" to what is happening in your Corvair electrically, which makes DIY maintenance almost impossible!

Give it a try! Don't let the appearance of the multimeter scare you away... after you play with it a bit, and perhaps watch a YouTube video explaining te operation of a multimeter, you will find that testing for the presence of voltage or for electrical continuity between two wiring points is not that complicated. If you click on the wiring schematic to enlarge it, you can locate the instrument panel bulbs, and trace the all to a common wiring junction point. Then follow the wire between that junction point to the fuse block, and from there trace it to the electrical switch.

Ultimately every electrical device in the car gets its voltage from the battery positive terminal. The other half of the circuit has a ground return to the battery negative terminal (via the vehicle chassis ground). The multimeter allows you to "see" this voltage, test for its presence, and determine where the interruption is so that the fault can be corrected. Electrical troubleshooting and fault isolation is a critical skill that you can easily learn. Just look at th wiring diagram as you would look at a road map, so that you can trace the electrical path from the source (battery positive) to the destination (battery negative, or GROUND).

1963 Corvair Passenger Car Combined Schematic

1963 Corvair Instrument Panel and Body Wiring Diagram

1963 Corvair Instrument Panel and Body Wiring Diagram (Dome Light Circuit)

When I was about 12 years old my father bought a HeathKit electronics learning system like the one pictured below. It taught me quite a lot about electronic circuitry, and later he purchased other HeathKits for me to build and learn on. That basic knowledge helped me to score well in a USAF recruiter electronics knowledge test when I joined the Air Force at age nineteen, which led me to a 24 year career in electronics maintenance with the Air Force.

[MonzaMike]

Thanks guys for the replies. As far as reaching the bulbs, I wear a size 17 ring. I probably can’t get to them as is. lol.
I’ve read quite a bit about the led’s. If I have to end up pulling the cluster out, I may consider those.
Brad, I guess I’ll get a multi-meter and learn it. I’ve spent all day today detailing the car. At 62 it beat me up pretty good. lol.

[bbodie52]

It doesn't get any easier... as my 71 year old back muscles keep reminding me!

[gbullman]

Just went through this with a friends 64, in his case it was insufficient ground for the dash lights only, turn signals and high beam indicator worked fine. In his case the car had been completely repainted and there just wasn’t good contact from body to instrument panel hood to instrument panel. We debated adding a ground wire directly to the instrument panel but we were successful just cleaning contact points.

[66vairguy]

Just went through this with a friends 64, in his case it was insufficient ground for the dash lights only, turn signals and high beam indicator worked fine. In his case the car had been completely repainted and there just wasn’t good contact from body to instrument panel hood to instrument panel. We debated adding a ground wire directly to the instrument panel but we were successful just cleaning contact points.

The wiper switch area on LM's wasn't painted specifically to allow for a ground. It gets rusty and then the wipers switch stops working. I painted the entire firewall and up under the dash so I had to install ground wires on the wiper switch and the instrument cluster. Not the difficult. One less thing to worry about in the future.

[RexJohnson]

On the late wiper switch there should be an internal "star" washer between the switch and the back of the dash to help get a ground.

[66vairguy]

On the late wiper switch there should be an internal "star" washer between the switch and the back of the dash to help get a ground.

Correct!

The other issue with the wiper switch is the terminal board has a blade riveted to it that contacts the wiper metal case that contacts the dash metal. That contact connection in the case goes bad with age. Like other's have done, I solder a ground wire to the "copper rivet" on the back of the terminal board. That is a permanent ground fix.

[MonzaMike]

Update*
Brad, I bought the multi-meter. Haven’t had a chance to get back on the problem yet. However, tonight we had a cruise-in at a local restaurant. We jumped in the Monza and drove to the event. As I drove, I worked the light switch back and forth CW then CCW then back, etc. again the dome light comes on instantly. As I drove home, I did the same thing off and on. By the time it started getting dark, I noticed I had cluster lighting. Not awful bright (but it was sunset not full dark). Now I have the source narrowed! I did notice that rotation is somewhat “grindy.” The click for the dome light is definitive but turning it off is not.

[N8]

You can take the headlight switch out and take it apart to clean it. You just have to bend some tabs on the housing to get it apart. If that doesn't work you can get a replacement. Or you can just skip right to replacing it. If you have intermittent lights and rotating the dimmer effects them working then it is definitely the switch.

[MonzaMike]

N8, yes when I first noticed it last week I had no cluster lights (although everything else worked great). Tonight I was just messing around for a few minutes moving it back and forth and by the time I got home the cluster lights were working. So I agree it must be worn out or corroded in there. As I mentioned above, it’s a definitive click when turning the dome light on but you don’t really feel it click as you turn it off.

[Frank DuVal]

Yes, it can be taken apart. But, look closely at the rheostat coil on the front first.

[vairmech]

If you pull the dash to change the headlight switch take the cluster apart then paint the inside of the shell white and add the LED's. I've done this on my 64 and you can actually see the complete speedo! The only downfall is there is no dimming or very little change with the LED's.

Now with that, I like a dim dash in the modern cars because I like to see what is in front of me OUTSIDE! When you have a bright dash glaring you in the face it reduces your vision outside. Try it sometime. BUT with the 64 and the LED's it wasn't offensive to me and didn't bother my vision looking outside.

[66vairguy]

The headlight "grinding" as you turn the knob is typical. There is a metal blade that moves across the resistance wire coil. After decades the wire and blade get corroded. Simply rotating it back and forth can clean up the contact if not badly worn. DO NOT lubricate the blade and wire!

Corvair instrument lights were never considered bright so most folks just leave the knob turned to maximum brightness. I have to agree with Ken that today's vehicle instrument lights tend to be much brighter.

The inside of the instrument housing gets dirty, simply cleaning it CAREFULLY will brighten up things. If you paint the inside use a high temperature white paint as that won't yellow with age.

There are dimmable LED bulbs available now, but they usually dim to only 50% illumination, the go suddenly go DARK. So the dimmable function is limited, but it works.