My 69 Hurst is equipped with Cruise Control that does not work. I am working through the cruise control system circuit by circuit. I hope to get it working again. I discovered that the cruise control switch on the brake appears to have been removed and replaced with a switch that activates the brake lights. The brake switch connector for the cruise control is not attached to anything. Where should the brake light switch be installed? I can't really track the location down in the various GM manuals, but I ma not sure it is not the position it is in now, which should hold the cruise control switch. I think the brake light switch may have been moved when a new power brake unit was installed by a previous owner.

In addition, it appears that the light in the main cruise control switch is not in its socket. I can see the light from the back of the dash, and it turns on with the switch. How easy is it to pull the cruise control switch to fix the light?

Will I ever use it?? Don't know. But since it came with the car, I want it to work.
Thanks,
Jay Morris

 

Cars with cruise control should have two switches, an electrical switch with two sets of contacts (one for brake lights, one for cruise control) and a vacuum vent switch that vents the vacuum in the cruise actuator for immediate release of the throttle.

 

What’s harder to find than the switches, is the retainers.

 

My '69 4-4-2 has factory cruise control and it was interesting to get it to work again after owning the car 22 years. I couldn't find anyone who had any knowledge of the cruise control system so I had to dive into it myself. First, you say the light on your dash switch works so that tells me the electrical side of you system has power as my system did the same thing. As far as the bulb goes, I suspect there would be a socket somewhere on the switch that the light just snaps in to such that the red lens on the switch would come on when you turn on the switch. Test your electrical end under the hood to make sure power is getting out there.

Second, the transducer used for the '69 A-body cruise control is unique to only that year. I've attached a picture of what it looks like. When I got to that part, I had the sense that it didn't work. I did have power to it but nothing was happening. I looked all over the internet for a another transducer of the same year and came up empty handed. I researched my unit a little more and found a man in Minneapolis MN that rebuilds 70-82 transducers and gave him a call. He said he would look at mine but there were no guarantees because it was a one-year-only unit and parts for it are scarce as hen's teeth. He was able to fix it (a bad solenoid of which he only had one of) and now my cruise control works as it should. There is a replacement transducer that doesn't look like the original but will uses the same bracket as the original and, with a slight re-routing of the lower speedo cable, works as well.

The system works on both electrical and vacuum and the cruise control switch at the brake pedal arm is interesting. Not only does it disengage the the vacuum system, it also disengages the electrical side such that if one fails, the other will still kill the cruise control.

If you do not have a Product Information Manual (PIM, aka assembly manual) for your '69, I strongly suggest buying one. It gives you the electrical and vacuum layout of the cruise control system. As well, I was also able to dig up a GM "Cruise Control Systems" product service training manual (22 pages) for this type of cruise control system (non-resume) that I will gladly copy and send to you if you send me your email address. My email is rkcorrigan51@gmail.com.

I've also attached a picture of the part of the system operated by vacuum from the transducer when the transducer is engage electrically via the "switch on" at the dash and pushing the button on the turn signal lever.

I hope this helps and that your cruise control system is pretty much intact. It's a rare option (even rarer on a '69 Hurst!) and a lot of people are amazed by it when they see it at car shows. Geez, back in '69 I would have been happy just to have A/C!

Randy C.

 

The retainer on the electrical switch is the same one used on every GM car built from 1964-mid 70s or later. This is not a problem. The retainer on the vacuum valve is the difficult one, but again used on every GM with cruise from 1969 through at least the mid-70s.

 

Thanks everyone for the information and advice. It looks like I am missing the switch that works with both the brake lights and the cruise control. Somehow, I missed that diagram in the manuals. I will go track down one of those switches.
I have the vacuum switch, but I do need to test it.
I have tested the engagement switch on the steering column, it looks like it is working properly.
After I get the brake switch, I will check to see if power is getting to the transducer. Then I'll check and see if it works. I hope it does not need a rebuild. Randy- thanks for the lead on the rebuilder.

The part that was missing when I got the car last April was the rod from the vacuum power unit to the carb linkage. I did manage to find one of those.

With the new switch i hope I can get it working again.

Thanks,

Jay