Cruise Control

[ryan427]

It's.... not working. Vacuum is good so I think it is the cruise control "unit". Just wanted to know if anyone knows of common problems. Just replace the control unit and presto?

 

[89Suburban]

You check the fuse? We do need a good tech article here how to troubleshoot them, unless it is already buried here somewhere. Also the wires in the T/S stalk can break where it pivots.

Mine is broken on the resume/accel button.

 

[Guardian]

Check the fuses first, always. The most common that I used to see was a bad fuse of a bad brake light switch.

 

[ryan427]

Check the fuses first, always. The most common that I used to see was a bad fuse of a bad brake light switch.

Thanks. Is there a fuse for the brake light switch? Or did you mean to say "a bad fuse OR a bad brake light switch". Sorry... I'm learning so not quite picking up on everything quite yet. I can pull all of the fuses and check them either way. Good advice.

 

[oneluckypops]

The switch has 4 wires that go to it. 3 of them go to the cruise control module, the other 1 is a power feed wire from the ignition hot.

Colors of the wires are:
Blue, Which is the 12 volt power supply from Ignition Hot.
Green, Sends 12 volts to the cruise control Module when the switch is in the on position. (cruise Input control)
Red, sends power to the cruise control module for the "set/coast" function.
Yellow, sends power to the cruise control module for the "resume/accelerate" function.

Color coding is for the harness on the switch itself, Vehichle harness may be of different colors. Also note that the harness from the switch is encased like an extention cord, so to test them you would need to peel back the outer casing.

But like was already mentioned, check fueses FIRST anf formost.

 

[ryan427]

Thanks oneluckypops. Great tech info. Will follow your advice and report back.

 

[skysurfer]

Mine wasn't working when I bought the truck, didn't really care because I don't use it, but while fixing something else I noticed a tear in the cc diaphragm. This is what it looks like. Replaced it and it works fine.

You must be registered for see images attach

My '84 had the button on the end of the stalk pop out. I was selling the truck and had to buy a new multi-function switch. (Expensive little sucker, currently $134) I couldn't figure out how to install it though, it involves taking the steering column apart so I tossed the new part in the glove box and told the new owner about it. If someone gets into installing one take pics and do a write-up.

 

[ryan427]

Mine wasn't working when I bought the truck, didn't really care because I don't use it, but while fixing something else I noticed a tear in the cc diaphragm. This is what it looks like. Replaced it and it works fine.

You must be registered for see images attach

My '84 had the button on the end of the stalk pop out. I was selling the truck and had to buy a new multi-function switch. (Expensive little sucker, currently $134) I couldn't figure out how to install it though, it involves taking the steering column apart so I tossed the new part in the glove box and told the new owner about it. If someone gets into installing one take pics and do a write-up.

Good deal. How much was the part? Can you replace just the diaphragm or is the cc unit all packaged together? I'll check that while I am checking the brake switch and fuses as I was advised.

 

[skysurfer]

The diaphragm comes attached to some sort of electrical component, Rock Auto lists it as a cruise control servo. The rebuilt part is $75, a new one is closer to $300.

 

[lusktommy]

Mine wasn't working when I bought the truck, didn't really care because I don't use it, but while fixing something else I noticed a tear in the cc diaphragm. This is what it looks like. Replaced it and it works fine.

You must be registered for see images attach

My '84 had the button on the end of the stalk pop out. I was selling the truck and had to buy a new multi-function switch. (Expensive little sucker, currently $134) I couldn't figure out how to install it though, it involves taking the steering column apart so I tossed the new part in the glove box and told the new owner about it. If someone gets into installing one take pics and do a write-up.

I have to change mine soon in my 84 ill upload some pics and do the write up on it no problem

 

[Jims86]

Mine wasn't working when I bought the truck, didn't really care because I don't use it, but while fixing something else I noticed a tear in the cc diaphragm. This is what it looks like. Replaced it and it works fine.

You must be registered for see images attach

My '84 had the button on the end of the stalk pop out. I was selling the truck and had to buy a new multi-function switch. (Expensive little sucker, currently $134) I couldn't figure out how to install it though, it involves taking the steering column apart so I tossed the new part in the glove box and told the new owner about it. If someone gets into installing one take pics and do a write-up.

CFM didnt send you the spacers for your throttle bracket?

 

[skysurfer]

Lol, I knew someone would comment on that and my money was on you Jim. The spacer on the truck right now is some no-name unit that a guy over at Pirate sent me for free. (Winning!)

The Super Sucker was purchased after that from craigslist but there was nothing included for the cable. My little Macguyver bracket seems to work fine so no plans to change it.

 

[Jims86]

Lol, I knew someone would comment on that and my money was on you Jim. The spacer on the truck right now is some no-name unit that a guy over at Pirate sent me for free. (Winning!)

The Super Sucker was purchased after that from craigslist but there was nothing included for the cable. My little Macguyver bracket seems to work fine so no plans to change it.

Right on!

 

[chengny]

Not sure if this is allowed (moderator please delete if against the rules).

I posted a ton of info on the cruise control system here:

http://www.truckforum.org/forums/ch...-wiper-and-cruise-inop-issues.html#post222327

Includes: troubleshooting matrix, vacuum routing diagram & schematics.