Tapping into the brake light switch

[565bbchevy]

So on my 86' regal with a 200R4 I am installing a B & M lock up controller and it says to tap in the brake light switch so that when you hit the brakes it disengages the lock up.
So is the switch normally closed when the brake pedal is not depressed or normally open?
Is this as simple as tapping into a wire on each side of the switch or is there more to it?

 

[pontiacgp]

one wire is always live so you don't want to tap into that side or the lock up will never engage

 

[pagrunt]

If you are still have the original switch just use the the plug ment for the computers signal for the lock up.

 

[fleming442]

To answer your question: the switch is normally open. Should be orange constant and white brake (only from the brake switch to the turn switch).

 

[oldsmobile joe]

RTFM, read the f--king manual. you want a normally closed switch which supplies power to lock up. when you step on the brakes, it will stop power flow and unlock the converter. review page 4 wiring schematics

https://documents.holley.com/70244.pdf

 

[fleming442]

Get a 4th gen F-body brake switch and pigtail out of a bone yard. It has both NO & NC switches and bolts right in.

 

[oldsmobile joe]

Get a 4th gen F-body brake switch and pigtail out of a bone yard. It has both NO & NC switches and bolts right in.

thats a great switch, i have several in my spare parts bin for future use.
but so is his factory switch that is already in the car and wired up. he just needs to use the correct wire coming out of the switch.

 

[69hurstolds]

This F-body switch you speak of, it's the early one? p/n 10194425?

Connectors would be GM# 12117354, (ACDelco # PT487) for the 3 prong, and GM# 12085488, (ACDelco # PT110) for the 2 prong, which is a super-common GM connector from door switches to coolant and brake light stuff.

If you snag any of these switches, they were used in 93-94 (and early 95- not sure when they went to 2nd design) F-bodies, as well, the same year Silhouette, Lumina APV, and Transports. The part number should be on the connector side of the switch so if yo use 10194425 on it, you're golden. As stated, snip the wiring and get the harness connectors too. If you buy them, you're looking at around $20 at the cheapest for the pair!

The switch is disco'ed, and no aftermarkets that I'm aware of.

 

[oldsmobile joe]

any idea what the differences are between 1st and 2nd design switches?

 

[fleming442]

I dunno, but mine came out of the 2002 Firebird I got the Series II from. It had (2) 2 pin connectors. I think I had to send both signals to the ECM, but not sure now.