havesometo

I'm going to try to finish up installing my 700r4 in 1980 this weekend. I'm installing a B&M locked up kit. The kit number kit is 70244. It is the mechanical one that works of the speedometer. This is were im confused about the yellow wire that hooks to the brake pedal. My car has cruise control. I've done searches and in some of those searches it says I need a 4 pin brake switch. Is that correct or can I use the one I have. If so how do I hook it up?

doorgunner

To keep things simple for now.....the yellow wire can go from the control box to the transmission connector so you can drive the vehicle without spending hours rewiring a new 4-pin switch into place.

(If the engine tries to stall during sudden stops, the yellow wire can be cut and routed through the brake switch---provided it is the correct style switch)

The thing to remember is---the section of yellow wire that goes from the brake light switch to the transmission connector should lose power when the brake pedal is depressed---and should regain power when the brake pedal is released-----the brake light switch should act like an emergency power cut-off when the pedal is depressed).

If the brake light switch is not capable of doing the above described actions, you may need a 4-terminal switch....1 pair of terminals to activate the brake lights-------and the other pair of terminals to temporarily interrupt power to the yellow wire that goes from the switch to the transmission when the pedal is depressed.

diehrd

Your 1980 has lock up already in it , It is vacuum controlled and located on the firewall just to the right of the break booster.It has a green wire that is used for the lock up and it is wired into the breaks already.

What i did was put a toggle switch in line with that green wire and a 4th gear pressure switch inside the valve body . This was cheap and fool proof.

7T1vette

Your brake pedal switch should already have a set of NC contacts for the brake lights and a NO set for the lockup and cruise control.

If you find that it does not, you can buy a brake light switch for an S-10 pickup with cruise control at the auto parts store, and just replace the switch you have.

Remember that the 'normal' position of that switch/pedal is NOT depressed has the plunger "engaged". When you depress the pedal, it releases the switch; so the contacts actuate in reversed action.

mrvette

Just be AWARE that I bought a 4 pin brake light sw for my '72, and the stupid normally closed contact set would open up when the switch got HOT, and so the converter would unlock, press on the brake pedal and it would allow lockup for a little while.....same thing, opens up and no lockup....drove me krazy for a while.....it was a popular brand too.....I'd trust none of them.....

stick a relay in there to open some contacts when actuated by brake light power.....that will release the 12 volts to the converter......

drwet

I wired mine to the existing cruise control switch on the brake pedal on my '79. Worked perfectly for years. Just remember it should supply power when the pedal is released, and cut power when the brake pedal is depressed.

I also installed a vacuum controlled switch which would cut power to the lockup if the engine quit (and vacuum dropped off).

doorgunner

Forget my crayon drawings.....I like the other members ideas better!

havesometo

Thanks to you guys I think I got it figured our.

doorgunner

Good! Post it using crayons...........so I can understand it!

My '34 SBC truck stalls out when one of my Loo-z-anna "neighbors from the Go-Cart Driving Academy" causes me to stomp on the brakes to save their life....