Headlight motor limit switch - 64

[Ed S.]

First, I know the device on the headlight motor is not an actual "limit" switch. That said, I have two questions about the small black device that everyone refers to as a "limit" switch. I have my motors & buckets out and completely rebuilt - I am in the reinstallation phase now.

Question 1. The "limit" switch can go on the bracket either way, does it make a difference which way it is installed? I am assuming having the mfrg. logo and part # facing out is the correct or preferred way to install it.

Question 2. The word "common" appears next to one brass terminal on the switch and the words "norm closed" & "norm open" appear next to the other brass terminal. When the switch is installed does it make a difference which wire with the small light blue connector goes on which terminal? I thought the switch just completes the circuit when the button is depressed and therefore it should not make a difference as to which blue connector goes on which terminal? If it is critical to get them on the "correct" terminals, how do you know which is correct?

[Stephen L.]

Re: Headlight motor limit switch - 64

ED, The black wire should go on the "Common" terminal. The gray/blue wire should be on the "NC" terminal. Operation of the switch should be that the switch plunger will be depressed with the headlight bucket FULLY open. The telltale light will be on with the buckets closed AND the headlite switch on until the buckets are fully open. At this point the telltale lamp will go off as the plunger is depressed.

[Ed S.]

Re: Headlight motor limit switch - 64

Stephen - Thank you for clearing that up. I have to take a closer look at the colors of the wires, I didn't know there was a difference - I was just focusing on the light blue connectors. What you say all makes sense.

[Ed S.]

Re: Headlight motor limit switch - 64

Stephen - one more question - the mounting of the "switch". Is there a preferred direction, should the company logo and P/N be facing out so it is visible? That would be my guess but I don't have a reference for that - or, does it not make a difference as long as the wires are connected correctly, as you described.

[Joe R.]

Re: Headlight motor limit switch - 64

Ed,

It makes no difference which wire goes where. Just as long as there is length on the wires to reach the terminal. No difference which end is mounted up or down. Just the length of the wires determine which direction.

JR

PS. The only thing this switch does is turn on and off the light on the dash!!!!!!!

[Stephen L.]

Re: Headlight motor limit switch - 64

Joe,
The switch is described by Ed as having a N.O. contact and a N.C. contact as well as COMMON. Therefore you need to be sure which contact is used as the dash light will be on when the bucket is fully open IF

[Ed S.]

Re: Headlight motor limit switch - 64

Stephen - as I understand your most recent post you refer to 3 contacts, a N.O, an N.C and a COMMON. The switch has two terminals - one marked Common and the other has Normal Open and Normal Closed next to it. I haven't completed the installation yet but I followed the advice you gave in your first response: Black wire to the Common terminal and the grey striped wire to the other terminal which is marked Normal Open and Normal Closed. Two terminals, 2 wires. That is it. I suspect that you are correct in that there is a right and wrong way to connect the wires - if that were not the case they would not have marked the switch with Common and NO / NC, nor would they have used two different colored wires. Thanks again.

[Stephen L.]

Re: Headlight motor limit switch - 64

Ed,
My misunderstanding. Evidently the switch plastic housing is used for either a N.C. or a N.O.
Under that condition, only 2 contacts, the wires can go either way. In electrical terms this switch would be considered normally closed (as if you had it in your hand) and held open in operation when the plunger is depressed.

[Joe R.]

Re: Headlight motor limit switch - 64

Joe,
The switch is described by Ed as having a N.O. contact and a N.C. contact as well as COMMON. Therefore you need to be sure which contact is used as the dash light will be on when the bucket is fully open IF

The switch has only two terminals and it is either open or closed. When the switch is closed the light comes on showing the headlights are on and the buckets are closed. There is no common on the switch. The switch is most likely used for other purposes in other GM vehicles.
The switch does say common on one end and the other end has norm closed and the other side has norm open. Just a multi-used switch.
Confusing, yes but just a switch open or closed.

JR

[Gene M.]

Re: Headlight motor limit switch - 64

A switch with three contacts is a replacement and not correct as the originals only had two contacts as Joe Ray states.