Questions and Answers

GMC Sierra Turn Signals & Cruise Q. My name is Thomas and I live in Sweden. I have recently bought a 1987 GMC Sierra Classic 2500 4x4 with a 6.2 liter diesel engine and TH400 and a new products transfer case. There is also a overdrive DNE 2. My problem is that the cruise control cables to the button in the turn signal lever has come loose. The colors is Red, Blue, Green and Red but which cable goes to where on the button?

I would also want to know from where does the cruise control get its speed signal? The overdrive doesn´t engage to high. I have checked the power and the shift relay and that works. The green light on the control is on and when I push the manual button the yellow HIGH light flashes for a ½ second.

A. As for the cruise, you need a new turn signal lever. Those wires are very small and fragile. Have never been able to fix one nor have I seen a schematic of that switch for the same reason. You can sneak the wires out of the column by tying a piece of fine wire onto the plug end of the lever.

Pull out the lever and wiggle the harness up through the column. Tie new one on and feed it back down. As for the over drive, it doesn't sound like it's factory installed, never seen one in the states. You may want to try to locate this company for a schematic and diagnostic charts.

The cruise control gets its signal from a Cruise Controls Vehicle Speed Sensor.