How does cruise work?

[Tony Hoffman]

As you look at the Pump in it's normal wrientation, there are two
terminals across from each other, and one on the top. The one on top
is the ground, the one on the right (as you are looking at the pump,
not the plug) is to seal off the vacuum dump (there is a relay inside
that does this) and the one on the left is what opperates the pump. I
just went through this on two 4000Q's in the last week. Both of them
pull great vacuum. One has a vacuum leak at the pedal switches. I
blocked off the line that goes inside to the two vacuum switches on
the pedal, and the cruise functions as intended. So, one of them is
leaking(should be able to fix that in the next couple of days. The
other never powers the pump, so there is more troubleshooting to do.

Anyhow, hope that helps,
Tony

>
> You can "hot wire" the cruise pump to test the system for leaks.  I
> forget which two wires to put ground and 12v on, though, and I don't
> think my diagram shows wire colors.
>
> --
> Huw Powell