Cruise Control Problem

[KikiPhillips]

I have never done any work on Cruise Controls (never had to) but now that day is here. My 1982 Corvette doesn't work at all. I don't even know if it has a light to say it's on? I've always heard that the main problem is cracked vacuum lines.

Any help and guidence would be most appreciated...

 

[Antz81]

I've always heard that the main problem is cracked vacuum lines.

That certainly would cause a problem, have you tested to check the condition of yours?

 

[Peer81]

There're perfect step by step rebuild topics on the net. I rebuild mine but still don't use is. There is no way to put your foot somewhere else besides on the gaspedal.

Greetings Peter

 

[KikiPhillips]

No I have not checked the vacuum lines. Is that the best first step? I'm hoping to get a laundry list of things to check (ie: check the fuse, power, relay(s), then the vacuum lines, etc. etc.) For all I know, that cable attached to it is broke?

I'm not playing dumb, I really just haven't touched one before.

Questions:
- Is there a light in the Dash, that comes on and lets me know the cruise control has been turned on?
- Are there fuses (maybe inline) and / or Relays?
- What does that cable do? (it looks like a speed odometer cable)
- If there is no On/Off light does it stay on?

Thanks in advance!

 

[Hib Halverson]

No I have not checked the vacuum lines. Is that the best first step? I'm hoping to get a laundry list of things to check (ie: check the fuse, power, relay(s), then the vacuum lines, etc. etc.) For all I know, that cable attached to it is broke?

I'm not playing dumb, I really just haven't touched one before.

Questions:
- Is there a light in the Dash, that comes on and lets me know the cruise control has been turned on?
- Are there fuses (maybe inline) and / or Relays?
- What does that cable do? (it looks like a speed odometer cable)
- If there is no On/Off light does it stay on?

Thanks in advance!

No light on the dash.
No fuse. Cruise on an 82 uses at the power accessory circuit breaker on the fuse panel under the dash, up high on the driver side.
The cable tells the cruise control system how fast the car is going.
No on/off light.

My suggestion is you buy the Factory Service Manual which has comprehensive instructions on how to troubleshoot and repair that system.

You can get an 82 FSM from CAC Sponsor Zip Products.

 

[Antz81]

My suggestion is you buy the Factory Service Manual which has comprehensive instructions on how to troubleshoot and repair that system.

You can get an 82 FSM from CAC Sponsor Zip Products.

Totally agree. It has troubleshooting guides for everything on the car.
I was a bit reluctant to get one when i got my car, but now I don't know how I survived without it.

 

[Lakeside49]

It is usually the transducer that requires replacement. I posted my successful replacement approach/steps here and on another main C3 forum about a year ago so you will have no issues researching. It was a satisfying DIY repair

 

[KikiPhillips]

Could you re-post that information on the transducer replacement, I'm sure something I'd like to print out and keep.

I'm gonna assume that the Transducer is the unit under the hood (drivers side) and the speed odometer plugs into it?

Here's another thing I discovered. There is a orange wire that plugs into it, I put my test light on it, turn the key on, clicked the cruise control switch (located on the signal lever) to on and the my test light barely lit up, I'm talking "Barely" but enough to see that turning the cruise control On/Off did something.

Also, my schematic shows me that there is some sort of switch associated with the brakes, that appeared to control a lot of stuff. Almost like everything ran through it...It also looked like it had a fat little vacuum hose on it.

Questions:
- The Transducer is under the hood...right?
- How many amps is that Orange wire suppose to supply?
- What is that big switch on my Brake Pedal?

Thanks for the Info and help....I do believe I will get that FSM as well....if I can find it.

 

[Antz81]

Could you re-post that information on the transducer replacement, I'm sure something I'd like to print out and keep.

I'm gonna assume that the Transducer is the unit under the hood (drivers side) and the speed odometer plugs into it?

Here's another thing I discovered. There is a orange wire that plugs into it, I put my test light on it, turn the key on, clicked the cruise control switch (located on the signal lever) to on and the my test light barely lit up, I'm talking "Barely" but enough to see that turning the cruise control On/Off did something.

Also, my schematic shows me that there is some sort of switch associated with the brakes, that appeared to control a lot of stuff. Almost like everything ran through it...It also looked like it had a fat little vacuum hose on it.

Questions:
- The Transducer is under the hood...right?
- How many amps is that Orange wire suppose to supply?
- What is that big switch on my Brake Pedal?

Thanks for the Info and help....I do believe I will get that FSM as well....if I can find it.

Yes the transducer is under the hood.
did the other wire onto it light your test light properly?
If the orange wire is the hold wire then it doesn't supply much, it has a resistance wire in it (this is why your test light was dim.)
the big switch on you brake pedal turns the cruise control off when you brake

 

[KikiPhillips]

I didn't test any other wires, although there is another one plug into it from the other side of the transducer. Also, the other wire (beside the Orange) was Black....I just thought it would be a ground? You're saying to check it for power?

 

[Antz81]

I didn't test any other wires, although there is another one plug into it from the other side of the transducer. Also, the other wire (beside the Orange) was Black....I just thought it would be a ground? You're saying to check it for power?

Ok just checked on the 82 diagram to confirm, no orange wire in the transducer, only green and blue (and black ground)
Youll need to find the transducer first. (You may have been at the resume solenoid)

 

[Lakeside49]

Go ahead and Google "1982 Corvette - Speed Control Replacement" and you'll find the strings that I used, and probably my posts. I can't help you with the testing, voltage, etc. But, the root cause of most 1980-81 C3 cruise control failure is the transducer. Perhaps you are the minority and that is not the issue with yours so no promises. I was initially skeptical until the thing suddenly, and joyfully sprang to life when I first pushed the cruise control engagement button on the turn signal stalk after replacing it. The original owner of my car said that it hadn't worked in many years.

The replacement was a PIA, but satisfying. If I had smaller hands it would have been no problem. Getting it out is harder than reinstalling it, but take mental note of how it comes out through that small opening, so that the rebuilt one, that you buy for no more than $125 plus core, can go back in the same way. And, since the speedo cables go in/out of it, be sure to pull them out from their housing (they come out and go back in amazingly easy) and lube them with either a dry graphite lube or, as I did, a light lithium grease lube. So, you will kill two birds with one stone. My only advise is to hire it out if you have especially large hands due to the comparatively small space next to the windshield washer bottle. It is not an overly complex repair. And, be sure to have a small flex socket adapter ($6 and worth far more in this repair) because it's the only way to get the right angle to remove and replace the two bolts that hold the transducer in place. It is not an optional device in this case. It is a DIY repair that you will be glad that you did if you are at all mechanically inclined because it is fun to engage it on a nice long stretch during that occasional weekend getaway. Pay attention to the adjustment instructions that are included. Mine will accelerate and additional 4MPH using the stock adjustment, though I couldn't care less - but, if you do, the MPH calibration adjustment is straightforward using the adjustment screw/nut on top of the transducer. I spent the good part of a Saturday morning on mine, and I'm glad that I did. Btw, while had the patient on the table, I pulled back the protective black rubber accordion cover on the adjacent speedo servo and sprayed some silicone lubricant into the servo housing, just to lube things up. Hope this helps you and good luck. Dave
p.s. add a couple of pieces of duct tape along the inner edge of the fender before you start in order to protect the skin on your fingers in the tight space. You will know what I mean if you don't. Good luck and enjoy that speed control. .

 

[KikiPhillips]

Thanks for all that info. I do all my own work so it'll be fun. I'm still restoring the interior right now, just got through sound proofing it with Fatmat and debating on using the "Reflectix" in the front floor board for keeping the heat out? I bought it already but slightly concerned of the thickness.

I did some more reading and the Orange wire I spoke of earlier (I found out) goes to the "Resume Solenoid". Like I said before the test light barely lit up when testing it. How can I tell if that Solenoid is good? Does it Pop in & out really hard so you know it works? or what? Is there a chance it's stuck and maybe the cause of my CC not working?

Thanks again for everyones input....

 

[Antz81]

I did some more reading and the Orange wire I spoke of earlier (I found out) goes to the "Resume Solenoid". Like I said before the test light barely lit up when testing it. How can I tell if that Solenoid is good? Does it Pop in & out really hard so you know it works? or what? Is there a chance it's stuck and maybe the cause of my CC not working?

Thanks again for everyones input....

Just check it for continuity to ground. As long as there is a circuit there you should be fine
Then check the transducer, (somewhere near the brake master cylinder) on-off-resume switch set to on. Unplug the connector and check for voltage on both wires don't worry if one is dim. If I you have voltage on both wires then check your ground. If of check for continuity between the hold wire(green) and ground. (About 5or 6 ohms).

 

[KikiPhillips]

Thanks for all the info....It'll probably be a couple of months before I have it all put back together and test the new transducer. Thanks again!