Unknown relay/switch

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Jan 22, 2007
Alva, Fl.
Have this relay or switch mounted just under the brake booster on my '77. Anyone have an idea what it's for? I can't find any reference to it in the Toyota Manual. It's the rusty-looking relay/switch just below the brake booster.
Thanks for any help,
Last edited:
the square thing ? - external voltage regulator for the alternator
"That little rusty box is probably the voltage regulator."

Not probably, Definitely... If it's rusty looking, replace it and save yourself a roadside breakdown....:cheers:
Maybe that's why the ammeter is jumpy at idle? Where to buy new???
Maybe that's why the ammeter is jumpy at idle? Where to buy new???

$25 or some from Specter Offroad - there are points inside (just as in an older model dizzy) that oxidize and can be cleaned up

if the ammeter jumps rhythmically, though, it could also be alternator brushes

oh, wait, I am seeing a connector just hanging there :confused:
oh, yeah, you are missing a windshield cleaning fluid bottle :doh:
ammeter doesn't jump with any regularity, so, based on your analysis, I think I may need to visit SOR
Yea, the loose connector IS the washer motor connector. Got a replacement bottle from my Buick Reatta that had a working pump(I think I posted pics in the forum). It'll do til I get an OEM. You folks on the forum amaze me--a simple pic and you can offer a ton of info--Thank you!!
OEM washer bottles exist only used, typically in bad shape - might as well get your Buick bottle hooked up

a loose bulb or wrong bulb can also cause wonky ammeter needle - check all your ground connections

BTW, it looks like your brake fluid is low
Ah, Claudia, saved me again. Took this little thingy apart and cleaned-little 400 grit sandpaper on the contacts, polished with the cuff of my leather glove, back together with a little dialectric grease on the gasket, and No more regulator jumping--smooth as silk
Had that little fawker go out on me in the middle of the night in bfe NC during a cross country road trip. Country roads; no lights; no fun!

Users who are viewing this thread

Top Bottom