Working on Cruise Control

[captndave737]

My cruise has always worked except for when the brake switch was out of adjustment. If the light doesn't come on when you hit set/coast then I'd say it's electrical.

 

[Tom Kelly]

My cruise has always worked except for when the brake switch was out of adjustment. If the light doesn't come on when you hit set/coast then I'd say it's electrical.

Probably correct! Unless the bulb is burned out. I will focus on power first and see where there is none. Thanks

 

[captndave737]

you can see if the bulb is burned out by going to the bulb position on the ignition key.

 

[Tom Kelly]

you can see if the bulb is burned out by going to the bulb position on the ignition key.

Thanks for the tip. Shows how hundreds of heads are better than one. When I turn the key to "on" only the "service soon" "seat belt" and "voltage" lights come on. I have the electronic dash. Not sure where the cruise light would be on that. Hard to replace? What bulb does it take?

 

[captndave737]

I don't know where it would be on an electronic dash. I have the factory service manuals and don't think it shows it. Might be in the owners manual.

I can't imagine it would be hard to change. on the standard gauge package it's quite easy, pull off the trim and unscrew the instrument panel to get at the back. They're peanut bulbs. Don't know what the number is though or if they're the same.

 

[Tom Kelly]

I don't know where it would be on an electronic dash. I have the factory service manuals and don't think it shows it. Might be in the owners manual.

I can't imagine it would be hard to change. on the standard gauge package it's quite easy, pull off the trim and unscrew the instrument panel to get at the back. They're peanut bulbs. Don't know what the number is though or if they're the same.

The service manual shows it on the right side at the bottom. I'll have a go today. Thanks again

 

[GNRick]

I have an AVC dash and have never seen the cruise bulb light up except for when I engage the cc.

 

[captndave737]

Well I could be mistaken. I thought all the bulbs tested in that position. I can't check now since the car's torn apart. I have an after market dash as well now.

 

[No disintegrations]

The cruise doesn't see TPS. It only sees the speed sensor output and the brake pedal. So if the cable were disconnected from the throttle, and the car fell below the set point, the servo would WOT trying to get the car back up to speed.

Mine quit working a bit ago. Replaced the servo to no avail. Tried to replace the module, but can't get one new or reman. I did go junkyard diving and came up with three boards that might work. The one I have in now has the same P/N printed on the board, but several jumpers are in different places. It tries to work with that board. I can set it, and I feel the servo moving the pedal, but it doesn't move it enough to maintain speed.

I have good vacuum at the servo and the brake switch isn't the issue. Cruise light comes on and everything. It just doesn't yank hard enough. Haven't been able to tell if the servo is weaksauce, or I need a different module.

I may look into adapting a newer cruise setup. Parts for this one are just hard to get.

Got any pics of the circuit boards? interested on the internals of it.

 

[Tom Kelly]

Digging deeper. I tried to "re-check" the five amp fuse at the most difficult spot I have ever seen a fuse. Seems okay. So I checked voltage at the actuator to see if there as any. With key on and cruise switch "off" no voltage. Made sense. With key on and cruise switch "on" got 7.8 volts in one of the five wires in the harness leading to the actuator. It was the one second closest to the engine and it was orange and black. Nothing on the other four wires. Does this mean anything? Does it eliminate any possible problems?

 

[Tom Kelly]

So still wondering if getting 7.8 volts on that one wire at actuator harness with cruise switch on means the problem is under the hood. Or if it means anything.

 

[1KWIKSIX]

I have an AVC dash and have never seen the cruise bulb light up except for when I engage the cc.

Hey GNRick,
I'd like to hook up cruise control on my car (which never came equipped with this option from the factory) , but am unsure how to connect this to my VDO external cable driven VSS, since my VDO gauges / set up came out of an AVC dash I used to have.

If you can give me some pointers or suggestions on how to do, I'd appreciate any help you can provide.
I do have all the cruise control pieces on hand, which I"ve collected over the years.

thx

dave

 

[GNRick]

Dave, I would have to check how the wires from the vss splice into the green buffer box under the dash. Do you need this info? Also, what else do you need to know? Do you need pics of the cable from the throttle to the actuator?

 

[1KWIKSIX]

Since my VDO speedometer is a mechanical unit, I don't use the factory (green) VSS box.....my set up uses a speedo cable driven VDO VSS sender which is located mid way on the 2 piece speedo cable directly underneath the brake booster.

 

[GNRick]

Does your VSS have wires coming out of it?

 

[1KWIKSIX]

Does your VSS have wires coming out of it?

Yup, it does
I can check the AVC installation instructions to let you know where these are hooked up to.

 

[1KWIKSIX]

I stand to be corrected. Looking at the installation instructions for the AVC dash and VDO gauges, (see 9, 20, 22, 39). I may have the factory green VSS sender connected to the VDO cable VSS sender. Been too many years ago when I installed these gauges.

Looks like the red wire was not used though.

 

[Tom Kelly]

As a wrap up to my original problem with my cruise control, I am happy to report it is working again. Mechanical ace Kevin at the Auto Center in Chappaqua traced it to the switch on the brake pedal which was not adjusted properly. I thought I had that covered but that's why we need people who know what they're doing. On a funny side note, although the cruise works perfectly, keeping the car right on speed very smoothly, I get no cruise indicator light. Figured it was the bulb so opened he bezel and discovered that there is no bulb, no socket, no "Cruise" on any of the light stencils. All this even though the car came from the factory with cruise (it's on the original window sticker) Go figure? Anyway, thanks for all your input. Great group and amazing wealth of knowledge within these halls.

 

[captndave737]

if you want to add a light tap into one of the Pink and black wires under the dash and run a wire to a bulb socket and run the other wire on the bulb socket to pin B on the cruise control module.

 

[captndave737]

if you want to add a light tap into one of the Pink and black wires under the dash and run a wire to a bulb socket and run the other wire on the bulb socket to pin B on the cruise control module