Fidgety brake light switch

I did a power disc brake upgrade last year and swapped out the pedal and brake light switch when I did it. Got flagged down yesterday and told I have no brake lights. I jumpered the plug, and the brake light circuit works fine. If I push up or down on the back end of the brake light switch, it activates. After pressing on it a couple times, it starts working again with the pedal … for a while.

Is there a trick for keeping the switch in the correct position or is mine just dying?

I’ve found that the spacer/washers are usually missing, or that the switch is wrong. Look at the manuals, double check the switch # and then hopefully you will solve the issue. The switch could be bad… due to such high standards in Mfg & testing!
P.S. There is supposed to be a 6" jumper cable w/ connectors. Vic has just repoped them…

I just ordered a new switch, bushing and washers from WCCC. I may try to shim a little piece of cardstock or something between the back edge of the rod and the front edge of the switch to tigthen it up enough to work to get to our club meeting Saturday.

I have a 68 and experienced something similar. At first I took the old switch off. Cleaned it up and sprayed with contact cleaner. With a ohms meter I could see that it was functioning again. However it only worked for a short period and degraded back to fail fast.

A new switch and plastic shim from WCCC was the permanent fix. I reused the retaining clip. Those are thick wire and look robust.

I did the Scott Drake switch and the three bushings from WCCC. Now the new switch keeps getting stuck on. The brake lights ran my battery dead in the parking lot at work Friday. I lubricated it and thought it was ok, but then after our club meet Saturday my wife went into the garage and said the brakes lights were on again.

It’s driving me crazy that after 2.5 years of heavy mechanical work, it’s a $10 electrical switch that’s causing problems and keeping me off the road.

I did notice my rod that goes into the master cylinder is round on top and bottom with just a flat section on the back of it whereas the shop manual photos show more of a G shape to the switch connection. It’s as if it had more flat surface area to keep the switch from tilting up or down.

I can’t decide if my next move should be to try yet another switch or to look at changing out the rod.

The switch is specific to power brakes versus manual brakes. I usually use only one side washer.

I’ve done the power brake conversion and switched pedals, and I ordered the power brake switch. Why only one side washer?

https://www.ebay.com/itm/Brake-Light-Switch-MOTORCRAFT-SW-862/303206828950?epid=81372269&hash=item4698890b96:g:XiEAAOSwDuld5ZZr

Maybe try getting a Motorcraft switch on ebay rather than the Scott Drake repro?

edit: I think I actually bought mine on amazon https://www.amazon.com/Motorcraft-SW862-Light-Switch-Assembly/dp/B0011DSQ8I/ref=sr_1_1?keywords=motorcraft+sw862&qid=1576790049&sr=8-1

I also have similar issue. I went to put my 67 away for the winter. Mine flickered on/off at first and second time the pedal us applied the brake lights stay on as it should. I haven’t looked at it yet, but I’m just assuming the switch is bad or loose. I just saw your post and thought I would share.