I am nearly finished with my T5 swap and I took it out for a shakedown run yesterday.

I now realize that I need a cruise control release switch connecting to the clutch pedal. I have the original vacuum/electrical release switch installed on the brake pedal and that works fine.
Do I need another one of the same switches for the clutch pedal?
Do I run a "T" of "F" coupling off of the existing vacuum line to both switches?
How do I splice a second release switch into the circuit? I don't really know the difference between "in series" and "in parallel" so, some specific instructions or a diagram would be awesome.

Also, is this the type of switch I need:

 

You don't need the vacuum release switch on the clutch pedal, just a momentary contact that splices into the existing brown/brown w/wht wires. When either electrical switch senses clutch or brake it'll switch the cruise off. Easy.

Cut the brown wire, connect both wires to a normally closed switch that's tripped by the pedal, and you're Crocodile Done-Dee.

 

I have an extra brake light switch. Could this be made to work? If so, how would I wire it ?

 

Sure. Ignore the three wires for the brake lights, because they're backwards from what you need. However the TCC part of the switch will work fine, so just wire the brown wires to the big exposed pins and you're done.

 

Why not?

 

Drew,

Thanks for your reply and the diagrams. I may just wire up my left over brake light/TCC switch as you suggest. Seems like an easy way to go.

However, I'm wondering if using a switch that has the vacuum port and running a vacuum line to both the brake and the clutch switches might provide some level of redundancy or fail safe in the event of some type of faulty electrical circuit. I see these release switches as a type of safety feature because I don't want to end up over-revving the engine by taking the car out of gear.

Again, any advice will be much appreciated.

 

GM didn't feel the need to run a vacuum switch on the clutch pedal. It's not a big deal, if you need to slow down you're going to be hitting the brake anyway.

 

Who says you're going to be slowing down when shifting?

I am remembering incorrectly. I could have sworn there was a vacuum switch on the clutch pedal. GM did change the setup with a manual transmission though

 

The vacuum valve is always on the brake pedal. GM used several different switches and valves based on year, trans, and with or without cruise.

While I've never bothered learning how the vacuum acts upon the cruise control, I know it's more of a secondary thing, the electrical switch will kill the cruise even without the vacuum purge. Otherwise you'd always have to hit the brake pedal to stop. However, you can turn the on/off to off at the lever, or tap the brake, or tap the clutch on five speeds.

 

I'm going to go ahead an wire up my left over brake light switch as you suggested. Thanks.

 

I was going to add a cruise control switch to the clutch pedal, but when I looked under the dash, I didn't see any brown wires connected to the existing cruise control switch on the brake pedal (the switch with the vacuum port). Here is a picture of the existing switch:


It looks like there is a pink and a purple wire.

1. Is this the switch circuit I need to tap into for the switch I need to install on the clutch pedal?
2. If so, would it matter which of the two wires I cut and run to the new switch?

 

Negative. Thats for the TCC solenoid for the automatic.

 

I assumed this was the switch for the cruise control due to the vacuum hose coming off of it.

 

Give me twenty minutes to edit photos and I'll show you....

 

So there are two brake light switches. The top plug with the Orn/Yel/Blu wires is the brake lights. The rear plug is different depending on equipment. The clear plug with the pink/blk and purple wires are for the torque converter clutch solenoid on auto cars. Auto cars without cruise got the brake light switch with the pins for the TCC on the back. All cars with cruise got the small connector for the cruise control interupt. When you've got an auto car with cruise, they put the TCC solenoid switch on the vacuum valve. Now why didn't they just put all the cruise stuff in one switch? I don't know.



Anyway, the blue plug is the cruise interupt. The small two pin black connector hanging out in the foreground above is for the clutch pedal switch. On 5spd cars, the brown wire from the blue plug runs to the clutch switch, and then back into the harness. So find the blue plug, cut the brown wire, connect your new switch in the middle, and you're done.

Oh yeah, 5spd cars have the vent hose all on it's own, on the brake pedal.

 

Switches on pedals...

 

This is great. Thanks for the fast reply. I'm going to get back to it tomorrow.

 

I intended to re-purpose the white switch but the diameter was too small. The black switch is the correct cruise cancel switch for a thirdgen clutch pedal assembly. I was able to find a nice one, that came out of a Firebird, complete with the pigtail and mounting band. I found it in the thirdgen.org classifieds for $10 shipped .



I spliced the switch into the existing cruise cancel circuit on the brake pedal. In my case, I cut the brown wire as described above and patched in the switch. Notice that the switch came with a mounting band which is a highly engineered piece that presses into the receiver on the clutch pedal assembly.



Here it is installed. It works well. Either the brake or clutch pedals will cancel the cruise control. HOWEVER, keep in mind that if you have the cruise engaged, and the manual transmission pops out of gear, you could really over-rev the engine by the time you think to tap the brake or clutch pedal. I don't plan to use use the cruise control until I have installed a rev limiter on the ignition (MSD 6AL). Thanks to everyone; especially Drew for contributing to my post and helping me get this figured out. thirdgen.org rules !