HEADLIGHT SWITCH

[corvairian1]

I changed out the headlight switch on my 65 Monza and threw out the old one. Since I mostly drive my Monza during daylight hours I didn't notice anything wrong until one evening when I turned the headlights on that the entire dash lighting was out even the gas gauge needle dropped down to empy and both the turn signal indicators turned on. The headlights and turn signals worked fine but everything else that was mentioned went haywire. So, I bought another switch replaced it and the same thing happened. One thing I noticed is when I would turn the knob on the switch which would be using the rheostat to dim the dash lights or turn on the interior dome & door lights (I don't have a dome light the car is a convertible) the turn signal indicators would come on and the gas guage would drop down to empty. The dash lights never came on. The original switch worked fine other than the knob was coming out. Unfortunately I threw it away. I read somewhere that you may have to break off the ground (rheostat) tab or tab #7 (there are 7 tabs on the switch as well as the grounding rheostat tab). Does anyone know about this or have any suggestions? All replies greatly appreciated.

[60vair]

you have a dash ground problem.
run a ground wire from gauge cluster to car body.

[Zaydenspapa]

Great fix! I discovered the screw to the Left of the steering column has a ground band that comes from the instrument cluster. Clean the band and the dash and the ground there fixes. THANKS FOR THE GREAT FIX!!

[bbodie52]

I am posting the pictures below to make it easier for others to visualize what you were describing. This is a common problem in 1965 and later Corvairs. The instrument panel is made of plastic, which is non-conductive. To provide the necessary ground path for the lights and electric instruments, Chevrolet installed a series of metal strips that daisy-chain from point to point around the back of the instrument panel. It finally ends up at a single ground connection that is attached by one screw to the metal frame of the dashboard. If this ground connection becomes loose, missing, or corroded you end up with either an intermittent ground connection or no ground connection at all, which as you discovered wreaks all kinds of havoc with the instrument panel lighting and electric instruments. The speedometer reading is not affected because it is a mechanical instrument and does not rely on electricity. Cleaning and reattaching the ground connection for your instrument panel will normally clear the problem, although problems can occur with individual instrument pods (on the Corsa only) if the connection becomes loose or corroded at that ground connection point.

Left-click each image with your mouse to enlarge the picture for better viewing…

1965-66 Corvair Instrument Panel Detail (Corsa)

1965-69 Corvair Instrument Panel Detail (Monza)

[66vairguy]

Great fix! I discovered the screw to the Left of the steering column has a ground band that comes from the instrument cluster. Clean the band and the dash and the ground there fixes. THANKS FOR THE GREAT FIX!!

Common problem and it may return. As 60vair said - run a good ground wire (10-12 ga) from the instrument cluster to a good body contact for ground.

Windshield wiper switch is another grounding problem area.