This is in my ‘30 Model A, no clue what the original application would be. Figured I would ask to see if these were fairly universal. Any thoughts on what part number or application to start chasing?
Any switch with 1/8'' pipe thread will work. There's at least 10 different configurations of terminals, so pick what serves you best with your wiring.
that looks like the type used on Fords....from the 40s-60s. SLS27 is a common part number, in stock at OReillys, etc. There are problems with how long they last, so maybe you'll want to dive deeper, but there are plenty of threads here about them.
Buy the one for motorcycles , the part numbers will always end with M , well I guess for motorcycles !!!
The older bikes had a switch with threaded studs. I'll guess and say mid-80s or older. But those may be obsolete by now, a bit of minor rewiring is easy. Harley didn't even use fuses until the plastic-bodied blade fuses showed up. Everything was circuit breakers. Seems the glass fuses couldn't take the vibrations...
My original switch had poles like the OP. Instead of cutting the ends off the harness I made jumper wires to adapt to the new HD style connectors. Now if I lose the switch on the road I can use either type.
Those stock Ford Pressure switches didn't last all that long on the cars they came on. I replaced a lot of them in the 70's The one I have on my 48 usually only lasts about two or three years at the most but I attribute that to where and how I drove it.
Mechanical switches are the best because you can adjust it so that after lightly pressing the brake pedal, the brake light will turn on before the car actually starts braking. I think it's an additional advantage to protect yourself from being hit from behind by another car
Painless Wiring also has a good one. I got one at NAPA that failed me. It started out fine, then took too much pressure to activate it. I have a good one I found on eBay. Also picked up a spare I carry around in the glove box.
Thanks for the help. Picked one up for a Harley Davidson application and it seems to work well. I did the same thing that Bandit Billy did with little jumpers. Stuck a NAPA spare in the trunk, so I can go back and forth in an emergency. Thanks again.
Thanks for the H-D part number. I've replaced the one in Clarence countless times in the 51 years I've owned it. I'll use a Harley one next time.
It looks like the one in Bob Drake's catalog. If you are running Silicon Brake fluid get one from Ron Francis Wire Works https://www.ronfrancis.com, (800) 292-1940. Normal switches won't last with Silicon brake fluid (don't ask me how I know). Charlie Stephens
Another issue could be moisture in the fluid. Brake fluid is a sponge for it and nobody ever flushes it out and change it
I have built 6 cars and used the hydraulic switch in all of them because they are simple, easy to install and , of course, replace. Also, the first build, an off topic car is still in service since 1970 and works fine. That car is a auto cross racer and gets severe use. I keep hoping I will find another switch to work that well but they haven't. In case you are wondering the initial switch came out of a 1964 VW. They obviously know something about brake switches the others don't.
When I first put my roadster on the road in 2009. I used a regular automotive hydraulic brake light switch. I went through several of them in short order. I use silicone fluid they apparently couldn't handle the silicone. I bought a switch from a Harley dealer and never looked back. That was in 2010. About 40k miles later and still working like it should. The only change necessary was changing the two connectors to match the Harley switch. Easy Peasy!
I've got a Ron Frances switch in mine, it's been on there for 6 years with no problem. I'm using silicone brake fluid in the brake system.
From the guy who currently has 5 Harley Davidsons sitting in my basement, spend the extra money and ONLY buy the Genuine Part from the Harley Davidson dealership. All the aftermarket ones are cheap shit, made in Asian countries.
I got rid of the hydraulic switch on my '55 Ford. Used a brake light switch for '67-72 Ford pickup. It's a push button switch (button in=off, button out=on) Drilled a hole in the pedal bracket where the rubber bumper on the pedal works the brake light switch.
https://www.speedwaymotors.com/Acce...ated,391417.html?sku=105181101&utm_matchtype={match_type}&msclkid=acab42fdf53810a80cd025bcb0ec6867&utm_source=bing&utm_medium=cpc&utm_campaign=SMI%20-%20Shopping%20(CSE)%20(Bing)%20(Brand%20Hybrid)&utm_term=4577404346894113&utm_content=All%20Products%20(Feb28_2020) https://www.amazon.com/Painless-80174-Pressure-Switch-Pigtail/dp/B00062Z53Y
The Jalopy Journal
