4 prong Floor Dimmer Switch

[traveler4life]

Hey Guys,
I have a 1970 Coupe Deville  and just found out the floor dimmer switch isn't working properly. It is a 4 prong switch that is bolted to the floor. Does anyone know where I can get another. I see a couple that are used priced over $ 200 , but run the risk of it too not working. Would rather buy a new one , if possible.
Need you to help me shine the lights.

[Barry M Wheeler #2189]

Why don't you see if any old time mechanics in your city/town might have an older Hollander Manual. This is a great way to see what other cars might use the same part. There may be a "lesser priced" car out there that used the same exact switch that your car does. (GM would use the same part on as many different cars as they could to save $$$.) And a Chevy part is possibly going to be priced lower than a Cadillac part. Good luck.

[Cadman-iac]

Hi Traveler,
It sounds like you have the "Guidematic" option that will automatically dim your lights in oncoming traffic.
Does your car have a sensor with a yellow lens mounted behind the grille? And there would be a control on the headlight switch to adjust the sensitivity of the system. I'm not sure exactly what it would look like, maybe a ring behind the headlight knob that you can rotate.
I'm not positive, but I don't think GM ever used the Guidematic on any other car lines, so you're stuck with finding one from a Cadillac.

Rick

[fishnjim]

Having computer/speed issues today, so try Standard products for dimmer switches.
You can use the readily available 3 prong, just have to delete the auto dimmer lead.

[Cadman-iac]

Having computer/speed issues today, so try Standard products for dimmer switches.
You can use the readily available 3 prong, just have to delete the auto dimmer lead.

I was going to mention that, but I didn't want to risk giving him the wrong information.

On my 56 that 4th wire is actually part of the switch, it comes out of the housing where the base is crimped in place.

The typical wire colors for the headlights are yellow, green, and tan, and the power wire for Guidematic is usually red.
Since yours is all in one connector, you will have to remove the wires from the 4 wire connector and install them into a 3 wire connector in order to get it to plug into a regular dimmer switch.

Rick

 Edit: well I just looked at the 70 service manual and I see that the dimmer switch has the regular 3 terminal connector on one side and a 1 terminal connector on the opposite side. So my advice to find a 3 terminal connector is not necessary. If you don't mind not having the Guidematic working, then you can replace the dimmer switch with a standard one, and tape up your 4th wire so it can't short out on anything.
 Here's a picture of the schematic for your system.