I have a 49 Buick, and a 50 Olds 88. Both used vacuum operated windshield squirters. I want to use the stock dash control, which is just an on off vacuum switch. Push the ****on you get vacuum at the other port. I need to find an electric/vacuum switch, that when vacuum is applied to it, it closes an electrical contact. I will use this to run a modern electric squirter pump. Hope this makes sense. Now all I need is the vacuum switch. Any suggestions?
My first thought was the switch GM used on 700R4's and others back then, low vacuum broke the circuit to lock up clutch I believe. Don't know how easy it would be to find used and aftermarket versions seem kind of pricey but what isn't these days. https://www.google.com/search?q=sup...6415025864819679,pvt:hg,pvo:3&oshop=apv&pvs=0
If you can't find one, I would think you could build an ***embly from a distributor vacuum advance unit and a universal motorcycle rear brake light switch. Just have the advance unit pull the brake switch closed. Really any automotive vacuum actuator can be used to pull the switch. Like from a heater box or similar.
1980's Ford F-Series. I.E. Bullnose trucks.... They had all the vacuum bits... Although at 40+ years old, "modern" may not quite be the correct term....
This is normally open, which is believe is what you want. Contacts are open until vacuum is applied, then it closes. https://www.amazon.com/dp/B000GZISJE/?tag=atomicindus08-20
All you need is an air switch like is used around water in your home. Garbage disposals to hot tub jets, they are just air switches that activate electric motors. I have air switches on my 442 to control the clicks on my QA-1 shocks so I don't have to crawl under it. They seem to never wear out.
I remember lots of cars in the 80's had vacuum operated everything, there were vac switches under the hood in a few places.. If it has 2 terminals and a vac. port, bring your multimeter and lungs to the wreckers and try them out.
I'm curious, does an air switch work on positive pressure? If so, that seems to be the opposite of a vacuum operated switch the OP is asking about.
Yes. It won't work. If it worked, it would work backwards. A vacuum switch, generally, requires more surface area because of the low pressure. It also needs to be 100% sealed so you dont have a vacuum leak. That is why they use diaphragms on vacuum operated switches, actuatos, etc.
No, I didn't mean just use the ****on but the electrical switch to which it is attached in order to power on and off the wipers. Personally, I would just stick an electric switch in the dash and put the original knob back on it, who cares if it pushes or turns? It will look correct.
This can't be that complicated. All I need is a vacuum switch that when vacuum is applied to it, it connects two electrical contacts together. Thus turning on my electrical washer pump.
I posted a link in post #8. Don't know what the current capacity is, so you might also have to use a relay but I doubt it.
Some Harley Evo Sporty's have a VOES [vacuum operated electrical switch] to retard ignition if the vacuum drops https://www.verifiedvaluevault.com/product-p-205913.html At low vacuum the circuit is open, at high vacuum the circuit closes
These are adjustable and with normally open or closed contacts: https://www.ebay.com/itm/177297757805?_trkparms=amclksrc=ITM&aid=111001&algo=REC.SEED&ao=1&asc=20211130125621&meid=06b20fee2b3142008c4892b41d2c87de&pid=101465&rk=3&rkt=4&sd=267450277206&itm=177297757805&pmt=1&noa=1&pg=3650466&brand=Unbranded&_trksid=p3650466.c101465.m3507 And affordable...
Looking at that last link, a fellow could simply mount a micro switch to a vacuum advance unit off an old distributor, a couple of small screws and a few holes and you would be good to go.
Thanks everyone for the replies. I have 2 switches on order and will report back when they come and I get one installed.
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