I have a 97 B3500 conversion van with the cruise control controls on the steering wheel, when I push the button the light will come on but the cruise control will not engage.
I have researched elsewhere and have tried- holding the set button for a long time. - hitting the steering wheel (it's supposed to free a stuck button) checked the fuse, all to no avail.
My heat vents work as they should so would it be a vacuum issue? how do I start to troubleshoot the issue?
thanks this forum has been great.

 

The switches just modify a voltage from the PCM. No fuse involved. They get a 5 volt signal from the PCM, and pressing buttons just passes said voltage thru a resistor. That tells the PCM what button you are pressing, so it has a clue of what it needs to do. Since the cruise lite comes on, you know you are at least getting the 5 volt signal, need to verify that the other buttons are actually doing something though. You can download the service manual for the 96-97 Ram Truck from here, It will tell you the values of the resistors in the buttons, and will have troubleshooting steps for the switches.... Start there. More often than not though, it just a broken vacuum line leading to the cruise servo. No idea where they stash it on the vans though.

 

Thanks this is most helpful I have a Haynes but there is not a lot in there.

 

Haynes and Chilton were fine, back in the days before tons of emissions equipment, and fuel injection..... These days, you need the proper manual to even have small hope of tracing issues..... The advance in technology does NOT make our lives easier in this instance.

 

Well, this might be far easier than I thought. We finally have some decent weather here and I got the dog house out (a task in itself) and traced the vacuum hoses it was off the vacuum ball. I hope that fixed it I will see after all the camping junk is put away and I can take it for a test drive.