'87 LT. I traced the wires that go to it from the brake pedal switch and they go somewhere behind the dash. Also, what do the vacuum hoses do in the cruise system?

 

The vacuum provides the power to open the throttle.

The controls that tell the vacuum how hard to pull are in the ECM.

 

It's hard to see the cruise control module, 'cause its black and blends in under there. Look under the passenger side dash it is just to the right of center. Not to be confused with the ECM which is the silver box under there, off to the far right side.

What exactly are you doing? Cruise not working?

 

My car was originally an LG4, the ECM is no longer there (non-CC carb now). I have a T56 and will be installing a Dakota box. The cruise actuator part with the cable was removed at some point but I have another to stick back in. I'm trying to find where the module is so I can run a VSS signal to it from the Dakota box. Where does the cruise system get its vacuum from? I have two HVAC hoses coming out of the firewall above the heater hoses, is it one of them?

Sounds like I might be in trouble, though, without the ECM there. If I stick an ECM back in will it work with just a VSS signal to it and no other sensors?

Whatcha shootin' in your avatar?

 

Just found the wiring diagram, the only thing the system needs from the ECM is the VSS signal looks like. So I guess all I'm not clear on now is where to run the vacuum lines.

 

The VSS signal comes from the instrument cluster, not the ECM. Look on that diagram you posted. "pin 8 inst clstr" You don't need an ECM to run the cruise control.

Vacuum hose runs from the intake (vacuum source) to a check valve, then to the vacuum tank. Hose to the vacuum tank has a tee in it with a hose that goes to the cruise servo. Another hose runs from the cruise servo to the vacuum release on the brake pedal in the car.
edit: the check valve also has a tee with a hose for the HVAC door controls.

Taurus 66, .357 mag
My photo is on the ranges web page http://www.pdhsc.com/competition.htm

 

With the T56 my speedometer doesn't work so the VSS signal will have to come from the Dakota box. On the hose that runs from the servo to the brake pedal I am able to suck and blow air through it, should I be able to do this with the brake pedal all the way up?

 

Ok, some progress. I found the cruise module and spliced a wire into the VSS input pin, now I'm just waiting for the Dakota box to get here. The brake release hose connects to a switch of some sort with a purple and a pink wire going in. It looks like it's broken though because there's a side missing. How is this supposed to be set up? And where do the wires go from the switch? I traced them to the big fat harness under the dash and that's as far as I could go.