Howdy Diesel Fans, I have a 91 Sub with a 4L80E, and a tps. I was wondering if the cruise works like the older C/K's with the pick up in the speedo or since I got a speedo-by-wire does my cruise work with the VSS? The point being I have no cruise. Will the older vacuum bellow assemb. work with a newer Vss system, if in fact that is what I have? Where would be a good place to start troubleshooting? I do have a good vacuum at the servo. I will check the stalk switch later today. Are there any other places I should check? And I believe the brake stuff is ok. Thanks in advanve, Artie

Check the brake switch.


On the large terminal vacuum terminal of the servo hook up a hand vacuum pump to the hose. That hose goes to the brake switch and should hold vacuum until the brake is pressed then it sould release.


The most common things to fail on these trucks are the servo and the turn signal lever.


There is a kentmoore tester that can by plugged in and test everything but the module.


Go here for more information http://www.rathwellhardware.com/technical.asp

I know these systems inside and out. Feel free to PM me or email me with any questions.

Thanks, Mr. Max Powers, I found a stalk switch bad, take a guess where? Yep, right where the cable exits the stalk. I would like to thank you for the link. The wiring diagram was good and was able to troubleshoot it in a matter of minutes. I'm gonna fake a switch to prove everything else is in working order, Thanks again, Artie

No problem. Let me know if you want to get a new switch. I should be able to sell it to you a lot cheaper then a GM dealer.

Hey thanks Max, I found the switch bad, and I also found a defective servo and a bad connecter on the servo's pigtail. I used the wiring diagram a lot, that was very helpful. I was glad to see that the site also included older C.C. that had a cable driven transducer. Thanks, Artie