84' vette

So I bought my car a few years ago, used obviously, and since then I have been fixing various parts of the car trying to get it into a smooth running vehicle. The issue I am currently working on is the cruise control. I get no response what so ever out of trying to engage the cruise control. If you guy's could lay out a systematic way of working through this to find the issue it would be greatly appreciated. Part of the reason I bought the car was so that I could learn how to work on cars, so i really appreciate any help from people who have experience, because as I said before, this is a learning experience for me.

jesredvette

I had the same issue with my '88. Main culprit with the cruise control are the vacuum lines. I replaced mine and it has worked fine since. Check fuse also.

AGENT 86

I'm not 100% sure my 86 info is the same as 84, but it will still help.

http://members.shaw.ca/dankai/Cruise%20Control%209C.pdf

http://members.shaw.ca/dankai/Cruise%20Control.pdf

sailorsteve

If your goal is to learn how to work on your Vette, do yourself a favor and get a Factory Service Manual for your '84. Do not waste your money on a Haynes or Chilton. It will be the best investment you could make.

DBo

Be sure to check the position of the switch on the brake pedal. Even if it's off by a fraction, it might not work. Low hanging fruit first: vacuum lines, brake switch, fuse.
Dave

markKlein

No offense meant, but do you know there is an on and off position on the stalk?

Definately check the fuses (numbers are in you owners manual).

crazedmav

I fixed my 84 cruise control recently. The recommendation about a FSR is right on - with it you'll find the problem quickly.
The main culprits are usually the vacuum lines or the brake (and clutch) vacuum switches.
You can also check the voltages and resistances of the servo if you have a voltmeter and the FSR.
Finally, check the connection in the servo-cable chain as someone on this forum suggested to me. Mine had too much slack (too loose) and would not engage. After replacing the vacuum lines (always a good idea) and checking everything else, I shortened the servo chain connection a few links and my cruise control came back to life.
Good luck.

84' vette

Alright so here's the update so far.
1st: I had checked the fuse a few months ago just to make sure that wasn't the problem, but I decided to double check it and it was ok. So its not the fuse.
2nd: I did know about the on/off position on the stalk, and no offense taken. The way i've been trying to engage the cruse control is by flipping the switch to the "on" position, and then pushing in the button on the end of the stalk. This is the correct method for engaging the cruise control right?
3rd: When replacing the vacuum lines, i'm assuming you are replacing the full length of the lines from the Cruise Control unit up to the front by the light and also the one that seems to go back into the firewall.
4th: The picture shows where it seems my hose has been "jerry rigged" by a previous owner, if someone else could post a pic showing where this hose was supposed to go that would be very much appreciated. Just to help orient everyone, this is a picture of the hose up by the front headlight. as you can probably see from the picture, the hose just has a screw in one end of it! [IMG]<a href="http://s1097.photobucket.com/albums/g358/ncpointguard/?action=view&amp;current=DSCN0308.jpg" target="_blank"><img src="http://i1097.photobucket.com/albums/g358/ncpointguard/DSCN0308.jpg" border="0" alt="Photobucket"></a>[/IMG]

84' vette

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84' vette

Hey thanks for those files, I've read through them and they deffinitely gave me a better sense of how the cruise control works, and I'm pretty sure that the system was the same between the 86 and 84!

AGENT 86

The vacuum line going towards headlights should be hooked up to the round vacuum storage tank.

84' vette

Yeah i pulled out the vacuum storage tank to make sure that the hose was hooked in to it, and in the pic you can see that it is hooked up. I'm assuming that originally there was just an elbow or the hose just went directly into the vacuum storage tank instead of having a "T" with one end having a screw in it?? is that correct? From the repair manual I see no reason for needing the end that has the screw in it so I might as well eliminate it. is this correct thinking? Also, since i don't have hose yet, but i do have a multi-meter, I decided to check the resistance across the cruise control servo, all of the resistances were within the ranges given in the repair manual. I didn't really feel like pulling out the dash to check the voltage and resistances there, so I will wait to do that until after I replace the vacuum hoses. [IMG][/IMG]

buzzlightyear

Are you having any problems with the gauge cluster? My 86 cruise control was't operateing until I had the gauge cluster rebuilt. Take the time and ckeck for the proper inputs and outputs from the cluster to the cruise control circuits. Good Luck

84' vette

I don't really have any major problems with the gauge cluster other than a few of the LED's are out and it is a little dim. From a functionality standpoint it seems to work just fine though.

mazdaverx7

does your 84 have the 4+3 trans or the automatic trans?

84' vette

It has the 4+3 speed

84' vette

Today I took off the interior panel that fits around the brake, clutch, and gas pedals so that I could get a good look at the Valve ASM, Cruise Electrical Release (Clutch) and Cruise Electrical Release (Brake). I found something that I was not expecting. It appears that I have no Cruise Electrical Release (Clutch)! I have uploaded pics that will hopefully demonstrate what I am talking about, I also uploaded a pic from a document that AGENT 86 posted which displays a diagram of how everything should be set up along with labels to everything. You guys can let me know if I'm just confused but i really think I'm missing the Cruise Electrical Release (Clutch)!!! I looked around and couldn't find any unused wires from the wiring harness.... don't exactly know what this means.....! Also, If at some point in time, the wiring harness on this car was replaced with one from an automatic..... which I don't know if that is possible or not.... could I still run the cruise control just off of the Cruise Electrical Release (Brake) and Valve ASM? The last two photos are taken from opposite directions, but trust the labels, they will help orient you. Thoughts and Ideas would be greatly appreciated!

AGENT 86

Looking at my 86 FSM, the same picture is used for starting clutch switch and cruise clutch switch (8A 201-4c). Maybe the same switch is used for both ?
I don't have cruise, so the FSM is my only input.

sailorsteve

You need to have switches on both the brake and clutch pedals. Do you have a wiring diagram? You can't run the cruise without a cutoff switch on the clutch because when you step on the clutch when cruise is engaged, the engine would accelerate.

L&MGraves

I have made so many upgrades to my Vette and its exciting to see it come up to quality. Cruise control is one of the last items to fix. I read all the suggestions regarding the cruise control but it seems the answers were for Manual transmission, mine is Automatic. does anyone have electric diagrams or photos that can help trouble shoot my cruise control that is on the windshield wiper wand? Thanks. LJ