Howie,
I just fixed my problem with the cruise control. I had the brake light on the dash constantly on.
I thought it was the parking brake switch underneath the dash so I disconnected it but that didn't turn off the dash light.
I then disconnected the brake fluid level indicator sensor which turned off the dash light. (I have to order a replacement brake fluid cap with the sensor built in (100 dollars))
So temporarily this solved the problem. Once the brake light in the dash was off, my cruise control worked. The parking brake still engages the brake light in the dash.
I'm just waiting on the new brake fluid cap with sensor so i'll know when my brake fluid level is low.
TJ
1991 Toyota Pickup 4x4 SR5