Early brake light switch question(s)

[TWJ]

Before I spend $80 on a new brake light switch for my '72T I thought I's make sure this is what I need. My brake lights don't won't and I know the following:

- Lights have worked fine for years then all of a sudden...
- No brake lights with everything connected as normal
- If I bypass the switch (with a short wire and connectors I made), with the ignition switch in the fuel pump on position, the brake lights come on fine.
- I tested the switch for continuity with an Ohms meter and it seems OK, that is full continuity with the switch in the brake lights on position and no continuity in the brake lights off position. (?????) Also checks out while in place in the peddle cluster in both postions.
- Power OK to the switch.
- Grounds recently been rebuilt.
- Bulbs OK.

Questions:

What can go wrong with this little "mechanical" switch?
Is there anything inside of the switch besides contact points that can go bad?
Is that switch adjustable?
Does the switch have polarity?

To make sure I have it connected properly...which pole does the power from the fuse connect to? Top (as you face it in the peddle cluster) or bottom?


Thanks for the help!

[JeremyD]

yes you can adjust. Make sure the tab has not been bent - that stops it being engaged when you let push the brake in.

[donporfi]

The switch is very simple, it is a rocker with two contacts. There is a lever that actuates this switch, when you depress the brake pedal, the lever does not touch the pedal and then the brake light turns on. You can adjust this switch with the small screw in the switch, it is very simple. With this screw you open or close the gap of the contact points. It is easier if you take the switch out of the pedal cluster, there are two screws to remove.
Really do not know what can be wrong with it, you tested what should be checked.

What I found in my switch was the corpse of a bug between the two contacts.
Brake Light Switch bugs

[blucille]

I had the same problems, adjusted the contacts, cleaned the contacts, but still had no lights....actually mine was always intermittent, so right after cleaning and adjusting they worked fine for a a short while

the litmus test is the one you describe, short the wires together, lights come on, everything is ok....so, clean up your switch, if that doesn't do it, you have enough corrosion or degradation of the contacts to warrant the $80 to replace the switch....

to me the $80 was a bargain compared to the constant disassembly/cleaning, etc, and the thought of having no brake lights

[bfunke]

I had same problem on my 68 after I rebuilt the pedal cluster. Turned out the PO had compensated for bad bushing and excess play by shimming the switch with a couple of washers. With new bushings the pedal didn't move as far and activate the switch. Removed the nonfactory washers and all worked as advertised. There is also a little adjustment screw and lock nut on the top of the switch.

[TWJ]

OK, I took the switch out of the car and did a mini-restoration job on it. I cleaned the connection terminals for the wiring. More importantly I took the adjustment screw out and discovered that it also acts a one half of the "contact points" which come together to complete the circuit and make the lights go on. Using a very fine jewelers file I cleaned up the contact point. Then using a jewelers small enough to fit through the slot were the actuator tab goes up and down I was able to clean up the other half of the contact points inside of the switch. Put it all back together and it works perfectly! SO, for now anyway, I saved the 80 bucks.

Thanks for the input and comments everyone!

BTW a set of jewelers files is a great little set of tools to have around, I use then frequently.

[Albuquerque]

Hi.
It's easy to remove only the switch without removing all the pedal cluster?
I've looked to the switch but I can't find that adjustment screw.
My brake lights only turn On when I completely depress the brake pedal.
Thanks for your help.

José

[RWebb]

Jose - search for some pics of the switch & pedal cluster to help you

yes, you undo 2 screws to remove the switch - IIRC, they face forward so are a bit hard to reach under there; you may want to remove the pedal cluster anyway if it has never been out (to check for rust)

you can move the adjusting screw - but anythig you do down there will pretty much require a mirror on a stick (they have ones lighted with LEDs now)

[donporfi]

You do not need to remove the pedal cluster.
Check the picture, the screw with the nut in front of the two spade contacts is the adjusting screw.

[Albuquerque]

Originally Posted by donporfi

You do not need to remove the pedal cluster.
Check the picture, the screw with the nut in front of the two spade contacts is the adjusting screw.

I understand now.
Thank you very much
José