1988 cruise control problem
 

guess my trucks a little old for some people. So my problem is that the crusise control is hard to get to engage. It is the type where you click the switch on the turn signal, then push the button and it should engage. Now I have to push the button like ten times before it finally engages the cruise. Can you give me a location and description of the part to replace. Think a used bone yard part is a good replacement. thanks

This just happened today to my 88'. I will be looking at the electrical diagram in the next couple of days. Let you know.

Same thing with my '88 lemme know if you find out anything.

I when thru mine last week. I used a friends all-data to find a wiring diagram.

With a VOM (DC Volts) you can do all of the troubleshooting from the harness that plugs into the cruise control actuator that's mounted near the brake booster.

I had two problems. There are two switches attached to the brake pedal that are wired in series. The easiest to remove, has two wires and it interupts voltage to the cruise actuator when you hit the breaks....it was sticking open. Advance Auto wanted $131 for the switch. I disassembled the switch and cleaned it with electrical cleaner and it worked as it should. I reinstalled it. I next checked all the other circuits and found no problems I looked into the actuator and saw moisture. I cleaned it but it still didn't work. I when to a Pick & Pull and got a used actuator for $13.75. I installed the electronics from the junk yard actuator and it worked. You really can't troubleshoot the actuator, just see that everthing else works and change it. There is a part number on the side of the electronic part of the actuator (you have to remore 4 screws and lift the electronic off to see it)....take with you to the junk yard. I had the rear wheels supended on jack stands while I did my testing. When you test the VSS circuit you have to be reading A/C on the meter.

The speedometer quit on my 88 Chevy. Occasionally when it worked, then cruise control worked also. Any idea how to bypass the speedometer? I don't particular care about the speedometer but I would like the cruise control to work.

If it's like my 85 Nissan the cruise and speedo work in harmony - don't get one w/o the other!

One needs the other.
 

The cruise control manages speed via a signal from the speedometer. You have to have a working speedometer or one of the speedometer control modules from a later year for it to work.

Sending unit
 

The problem with your speedometer and cruise control will either be the sending unit on the transmission or (depending on the year) the speedometer itself (which houses the converter that translates the signal from the transmission for the speedometer and cruise) or a standalone converter located under the dash close to the glove box that supplies the signal to the speedometer and cruise. Being an 88, yours should be built into the speedometer.