Cruise control

[Mr.Chevy]

Hey guys,

Newbie question here Is it possible to add cruise control on a 1987 r10?

 

[74 Shortbed]

Sure you can, probably find the whole thing at a junk yard, or you could go aftermarket too.

 

[1987 GMC Jimmy]

The junkyard idea should work well. I'd say the biggest thing to look for is that the cruise servo rubber isn't slashed. Don't pay much attention to the turn signal stalk from a junkyard either. Those things are dirt cheap.

 

[HotRodPC]

None of y'uns going to esplain there is different methods for the different year models? All the answers above are right. You can add cruise control to about anything. When I got my 86, I couldn't believe, with exception of the AC which I knew didn't work since there was no belt on the compressor, everything worked including the Cruise Control.

You're truck being an ECM controlled TBI truck, you'll already have part of what's needed. You should have the little green box behind the dash cluster. That green box is a converter off the speedometer to make a VSS (Vehicle Speed Sensor) for the ECM. In 90 Burbs, Blazers, Jimmys and Crew Cabs the transmissions or Transfer Case if 4x4 went to an actual VSS.

Point is, you'll probably need to get your parts off an 87 truck, or 87-89 Burb, Blazer, Jimmy or Crew Cab. Servo brackets that mount the Servo you'll probably need to make sure you're getting those off of a 305 or 350 since they're likely different on a 454.

I myself would take the time to find the OEM GM Factory set up though. I've seen some aftermarket kits and they not only looked like an add-on after thought, they didn't last very long.

 

[74 Shortbed]

I've seen some aftermarket kits and they not only looked like an add-on after thought, they didn't last very long.

This is one of the best out there, you can get them that look like factory, had one for 10yrs in two trucks then took it out when I sold the last one, now it will go in my C-10 when it's done, they're also adjustable..
http://www.rostra.com/universal-aftermarket-cruise-control-by-rostra.php

 

[Mr.Chevy]

Thanks for the info guys!

 

[spanky55amg]

Can I hijack this thread.
84 cruise control. I still have the original RPO sticker and it was installed on the truck. My stalk, ass-u-ming that its stock, has CC.
http://www.justanswer.com/chevy/1sx...ontrol-servo-vacuum-line-diagram-picture.html
looking at this diagram, it answered what the big vacuum tank by the driver's firewall is, which I now know is the accumulator. And now Im trying to go thru pictures. But I dont think it was connected by vacuum. Lets assume that all the vacuum lines are there.......
Am I correct in assuming that CC will not work if the speedo cable needs to be replaced b/c it is bouncing. Now all of the sudden I have to try to make this work. I NEED CC.

 

[1987 GMC Jimmy]

Yeah, I'd make sure the storage canister/accumulator or ball as people like to call it is part of the equation. On mine, you have the line that comes out of the back of the intake, a one way check valve that splits off to go to HVAC mode control and then towards the storage canister, and finally an inline vacuum barb right before you get to the canister with one side going into the canister and the other going to the cruise servo. The thing about the speedo cable... I don't think it would have an affect. When I hit bumps in my Caprice my speedo cable bounces everywhere, but it keeps going like nothing happened. It didn't work when I first got it. I got a troubleshooting diagram off here, and I hooked a test light to a wire that was supposed to energize with the key on and the slider moved to on. I want to say the pink wire, but it was a while ago, and that could be wrong. When I moved the slider, nothing happened. I replaced the stalk and that restored cruise control. The servo works in my Jimmy so my car was the best anecdote for your intents and purposes, I think.

 

[Jrgunn5150]

Can I hijack this thread.
84 cruise control. I still have the original RPO sticker and it was installed on the truck. My stalk, ass-u-ming that its stock, has CC.
http://www.justanswer.com/chevy/1sx...ontrol-servo-vacuum-line-diagram-picture.html
looking at this diagram, it answered what the big vacuum tank by the driver's firewall is, which I now know is the accumulator. And now Im trying to go thru pictures. But I dont think it was connected by vacuum. Lets assume that all the vacuum lines are there.......
Am I correct in assuming that CC will not work if the speedo cable needs to be replaced b/c it is bouncing. Now all of the sudden I have to try to make this work. I NEED CC.

With a vacuum system like you have, it doesn't care about the speedo cable, you could cut it out and the cruise would still work.

 

[spanky55amg]

With a vacuum system like you have, it doesn't care about the speedo cable, you could cut it out and the cruise would still work.

I was wondering and I wasnt totally sure if that diag was specific to us. But it did have a connector on the back of the speedo which confused me b/c I didnt know if any electronics like that ran to the speedo.
So then all I have to make sure is that the vacuum lines are connected and there are not leaks. I think most if not all of parts are still on the truck.

 

[HotRodPC]

With a vacuum system like you have, it doesn't care about the speedo cable, you could cut it out and the cruise would still work.

I don't know that this is true Jr. I'm no expert on CC but follow along for a second and see if this makes sense. I agree in the later trucks the CC IS NOT like the old units where the speedo cable is 2 pc and goes through the box as older units did. However, the 80's trucks have that green plastic converter box that comes off the speedo right? So if the speedo isn't being operated by the speedo cable, then the green box doesn't have anything to read that it can convert to a speed signal. And could it be possible if his speedo needle is bouncing, that it would make it hard for the green converter to count and read the signal coming from the speedo. Again, I don't know for certain. Just thinking technologically and wondering where the info would come from if the speedo cable didn't play a part???

 

[Jrgunn5150]

I don't know that this is true Jr. I'm no expert on CC but follow along for a second and see if this makes sense. I agree in the later trucks the CC IS NOT like the old units where the speedo cable is 2 pc and goes through the box as older units did. However, the 80's trucks have that green plastic converter box that comes off the speedo right? So if the speedo isn't being operated by the speedo cable, then the green box doesn't have anything to read that it can convert to a speed signal. And could it be possible if his speedo needle is bouncing, that it would make it hard for the green converter to count and read the signal coming from the speedo. Again, I don't know for certain. Just thinking technologically and wondering where the info would come from if the speedo cable didn't play a part???

The way I understand, the newer trucks, use the VSS and control speed in the ECU.

The vacuum trucks just locked the throttle position and the can drew harder when load was increased to maintain the locked position. In essence, they read throttle position, not speed.

I have been wrong before though.

 

[TIE_Fightertk06]

I an affirm: the vacuum servos lock throttle position after actuation. That's the best, in my opionion, system to retrofit. Fewer parts to swap and it's a snap to install.

 

[HotRodPC]

The way I understand, the newer trucks, use the VSS and control speed in the ECU.

The vacuum trucks just locked the throttle position and the can drew harder when load was increased to maintain the locked position. In essence, they read throttle position, not speed.

I have been wrong before though.

You may be totally right. It just seems to me the converter box takes the place of the VSS in the older trucks for the CC. I see what your saying, but I'm just curious how would the CC know when it reached the locked speed position if it was climbing a hill or from over speed if it were going down hill. Just seems it would need to know the speed somehow. It's all assumptions on my part cuz I sure don't know for certain at this point. I may know later on. Now my OCD will make me study it to find out dammit.

 

[Jrgunn5150]

You may be totally right. It just seems to me the converter box takes the place of the VSS in the older trucks for the CC. I see what your saying, but I'm just curious how would the CC know when it reached the locked speed position if it was climbing a hill or from over speed if it were going down hill. Just seems it would need to know the speed somehow. It's all assumptions on my part cuz I sure don't know for certain at this point. I may know later on. Now my OCD will make me study it to find out dammit.

When you go up a hill, the engine goes under load, which increases vacuum, and pulls further on the throttle. IN general on carb'd applications.