The Stovebolt Site Forums The Shop Area The Electrical Bay Reverse light switch

In my '63 I have a 4spd Muncie with a Hurst shifter. I am looking for a plunger type switch to activate my reverse lights when the shifter is engaged in reverse. I found that the brake light switch is perfect for this application in regards to physical size, but when the plunger is depressed , it breaks the contact and turns out the reverse lights, instead of making the connection and turning them on. Is there anything similar to this switch out there that is a normally open switch as opposed to this normally closed swith?

Some brake light switches have an extra set of contacts used in the cruise control system, and I believe they're normally-open, closed when the switch is depressed. A simpler method would be to go to an industrial electricity supply store,(W.W. Grainger is a good one) and look at their selection of "microswitch" products. They come in several shapes and plunger types, and most include a "common" terminal, and nrmally-open and normally-closed contacts. I used a lot of these types of switches when I was an industrial maintenence technician, and they've got a lot of automotive applications.
Jerry

If the brake light switch fits the mounting location and you cannot find an acceptable switch, you can still use it. You only need to add a relay with normally open and normally closed contacts. John Deere uses one in their MFWD circuit on 55 series tractors. I can get you a part number if you like--I don't have it in front of me at present. This relay is made by either Hella or Bosch.

Anyway, when the reverse lever actuates the plunger on the brake light switch, it opens the contacts. Hook up the relay so that the light power source wire goes to the #30 terminal and the wire going to the lights is attached to the #87a terminal(normally closed). Feed the brake switch from ignition switched 12 volts and have the switched wire feed the #85 terminal on the relay. Ground the #86 terminal and you are set.

A relay, especially one with normally open and normally closed contacts, is a very useful electrical component.

Thanks for your advice and suggestions. I picked up a brake light switch for a vehicle with cruise control , the kind with the extra contact , and now everything works like I want it to.

Greg63,
I'm installing a reverse switch into my SM420 tranny. When the plunger is depressed, the circuit closes sending voltage to the lamps. The switch is Napa's # NS119.

I actually haven't physically installed it yet, only mentally. Need to find time.