I have a question regarding the correction operation of the cruse control shutoff switches for a manual transmission. I car was originally a automatic but I swapped in a 6 speed manual transmission. My cruse control still works and will shutoff when I hit the brakes. However, if the cruse is set and I hit the clutch it will not turn off and the engine will red line if I don’t shut it off, no supprise there. I want to wire up a clutch shutoff switch to prevent the engine from over revving when I press the clutch.

So the question is how is it supposed to work from the factory if you have a manual transmission? When you press the clutch is this supposed to turn the cruse off or is it only supposed to disable it while the pedal is depressed and re-enable when the pedal is released? I other words, if the cruse is set and I press the clutch in to shift gears, when I release the clutch should the cruse reengage or do I have to hit the resume button?

I know how to hook it up for either scenario but I’m just wondering how it is supposed to work.

 

My research in other makes (two non-camaro, both GM) show the cruise control manual transmission switch inline with the brake switch. So hitting either one disengages cruise control until you manually reset it.

Hope that helps!

 

With the curise control on my auto 82 Z28 the curise is disable whenever you hit the brake. You had to press the resume button to reenable the curis function.

Cars equipped with the manual transmission operated the same way. However both the the brake and cultch pedals had a vaccum switch, which were in parallel. If you depressed either pedal, the vaccum switch would vent the vaccum signal to the servo assembly. This would disable the curise function until Resume was pressed.

I don't know if your model year has vaccum or electric switches, but as dyeager535 notes, both need to be in parallel and disable the curise function until the Resmue button is pressed.

I can post the 82 vaccum and wiring diagram. However I do know that in 85 or so the curise control transducer was changed and some of the connections are different than in 82.

If you just have a single vaccum line from the cruise servo to your brake pedal, put a TEE in the line and run a line to the vaccum switch mounted on the clutch pedal.

Dave

 

I'm kind of curious how necessary those vacuum switches are.

If you play around with the servo's (or just read the manual lol) you'll find that without power, the cruise servo vents anyways. So not sure why it's needed if the brake/clutch switches cut power.

 

Someone correct me if I'm wrong, but shouldn't the electric switches be wired in series? Parallel wiring would mean if one is open, then there is still current flow through the other.

 

Series is what I meant, although I said inline. The wire that feeds voltage to the cruise module passes through BOTH the clutch pedal and brake switches.

 

Yes, the electrical switches are in series, the vacuum release ports are in parallel.

The electrical switches server as a primary disable circuit. If they fail (connector falls off, wire is shorted, whatever), the vacuum release is a secondary disable circuit, a failsafe if you wish.

Look at the diagram below, specifically top left part. That's the difference between automatic and manual equipped vehicles.

Hope this helps.
Lou

(click on picture for exploded view)

 

Ok, so the vaccume switch acks like a backup in case the electrical switch fails and both switches are supposed to be hooked up to both brake and clutch pedals.

In playing with this setup I was able to put a vacume switch on the clutch pedal and connect the vacume line to both the brake and clutch vacume switches use a T (parallel I believe). This allowed me to have the cruse set and when I pushed the clutch it would temporarily disable the cruse so I could shift gears and then the cruse would resume when I let the pedal back out.

Apparently this is not the way it is supposed to be hooked up but it was kind of nice. For example, if you had cruse set and you wanted to downshift to go up a hill or something. Not that I would need to since I can go up most hills in 6th gear. Can anyone think of a problem with hooking it up this way?

 

You are right, this is not the way it's supposed to be hooked up. It would not be safe to do it this way.
For example: you are cruising around, depress the clutch and put it in neutral. What happens when you release the clutch? The motor revs up to red line and rev limiter keeps it there.

I think I might have an extra cruice control switch at home, I'll look. Although, I'd assume you could buy one at your local car parts store.

Lou

 

True. I'm sure I can pick up a switch at the auto store. Thanks guys. At least now I know how it's supposed to work.

 

any updates?