I am installing a clutch safety switch on my 77 and ran into a couple issues I was hoping someone could help out with..

The previous owner did a four speed conversion and Mickey Moused the wiring to make it start with a 12 gauge wire. Needless to say, it failed. I found the original neutral safety switch wires under the center console and pulled them back. to the clutch area so all set there(minus the connector). I pulled the clutch/brake pedal assy out (that was fun) and found my pedal is not drilled for the rod. It looks like my bracket has the correct holes for the switch so I think I am good there.

1. Can someone give me a measurement from the clutch rod to where the hole should be drilled and if possible the diameter of the hole?
2. I noticed that there is a vacuum switch next to the brake light switch. It did have a hose connected to it. Is that for cruise control? If it is for cruise control, where would the controls be?
3. Are all the safety switch kits out there the same or is one better than the others?
4. I found the wire extension on many sights(pigtail image attached) but I do not have the male end to plug into it. Anyone got one?


I attached a couple of pics. The assembly with the switch is from ebay. mine is the rusty looking one for the moment.

Thanks

 

The vacuum switch on the brake pedal is there to release the throttle when using cruise control when you tap the brake pedal.

The cruise control transducer is under the master cylinder. The speedo cable from the transmission goes into the transducer. A short cable out of the transducer goes to the dash speedometer.

The safety switch extension plug you can just make yourself with 2 crimp on female spade terminals on the end of the wires that attach to the switch. That's what I did. I did cut the 6" extension wires off the automatic shifter to start with so I already had that plug connector that attaches to the harness.

 

Any thoughts on where the cruise control switches are supposed to be?

 

There would be a switch on the end of the turn signal stalk. That, the transducer and the pedal vacuum break switch/hose is all there is. There is a good description in the factory service manual for my '80.

You can probably eyeball the tiny hole in the clutch pedal once you have the switch and the link rod installed. Its not super critical.

Do you have cruise control on your car now? Little known fact - The factory never could figure out how to do cruise control on a manual transmission C3 so they never offered that on your '77 or even my '80. Mine still works after the manual conversion but if I hit the clutch while cruise is engaged, the RPMs would probably climb very high immediately. The simple fix seems like it would be to add another vacuum switch to the clutch pedal but GM never did that, so I would guess it was a bad idea. If they could not figure it all out, neither will I.

If you still need the safety switch extension harness, another option is to just buy one. Not terribly expensive if you do not want to make your own.

 

The turn signal switch on my 77 has the wiper controls on it. I couldn't find a replacement that had the cruise button on it. I agree on the danger of pressing the clutch with it engaged. My C4's all had a second vacuum switch to disengage the cruise when pressed. Anyway, it was just a curiosity as I couldn't find any remnants of the switch assy.

Thanks

 

How hard was it getting the pedal assy out?

 

It wasn't too bad once the steering column was out and clusters pulled.

 

Thanks

 

Here is where js is curently at.