Double Throw Brake Light Switch

[CTX-SLPR]

Howdy folks,



I'm on the hunt for a double throw Normally Open (NO) brake light switch that fits the standard GM screw-in placement. I can find combo switches that do NO for the lights and Normally Closed (NC) for the other positions but I need a double NO switch for the combo of brake lights (12v) and Microsquirt brake apply (Grnd). I can put a relay to invert the signal but I'd rather not cram another relay under the dash. Any suggestions?

Thanks

[dontlifttoshift]

The microsquirt needs to see ground when the brakes are applied?

[ween]

If I recall, a 3rd gen f-body has a brakelight switch with 3 contacts, isolated till released then all connected...normally open for brake light circuit and 3rd brake light. and also has the NC contacts.

[CTX-SLPR]

The microsquirt needs to see ground when the brakes are applied?

Microsquirt transmission controller needs it for TCC release

If I recall, a 3rd gen f-body has a brakelight switch with 3 contacts, isolated till released then all connected...normally open for brake light circuit and 3rd brake light. and also has the NC contacts.

I have a 4th Gen F-body now which has the front terminal pair as a NO but the additional set of pairs are a double throw NC set. I'll check out the 3rd Gen switch.

[dhutton]

A little messy but if you have unused master cylinder ports you could use one of the hydraulic pressure brake light switches.

[CTX-SLPR]

A little messy but if you have unused master cylinder ports you could use one of the hydraulic pressure brake light switches.

Since the microsquirt is inside the cabin that's a last option.

So far all I can find is switches with a single NO pair and 1 or more sets of NC terminals based largely on how GM implemented the added functionalities like lockup converters and cruise control that go open when applied vs. the lights that go closed. I guess I get to mount another relay up under the dash off of the NC side as it's easier than rewiring the lights as well. Technically I could use the current output to run to the L67 ECM incase I wanted to add cruise at some point but am less concerned about that vs. getting the core systems working.

[ween]

https://www.rockauto.com/en/parts/st...t+switch,10474

[CTX-SLPR]

https://www.rockauto.com/en/parts/st...t+switch,10474

Looks promising from the T-type wiring diagrams and some general feedback on some folks trying to wire up 3rd brake lights on earlier cars.

Got one on order from Amazon to try out.

Thanks!

[CTX-SLPR]

Switch finally arrived and it has a three terminal NC section and a two terminal NO section. Unfortunately, the three terminals all gang together so I could have lights or a signal but not both since the microsquirt specifically says do not put 12VDC onto the pin. Looks like I'll have to put a relay on it after all...