Cruise control stopped working

[Daryl]

CC was working fine time before last I drove it. Any thoughts/ideas/clues as to why, for no apparent reason it stopped working??

Thanks!

 

[shovel]

check your taillight bulbs.

 

[ttocs]

fuses

 

[Daryl]

Ok gents, will do tomorrow after work. Any chance it could be vacuum related?

 

[95opal]

Ok gents, will do tomorrow after work. Any chance it could be vacuum related?

Possibility is there.

 

[joemomma]

Could definitely be vacuum line-related. When I was chasing my idle hang, I found some bad lines and replaced them. Just so happened to fix the CC.

 

[AUSN95]

If mechanically it all checks out & the buttons on your steering wheel are what’s causing the trouble:
Your clockspring might be on its way out - this is a common symptom of one that has already failed.

 

[Daryl]

Thanks, I’ll check it out

 

[Daryl]

If mechanically it all checks out & the buttons on your steering wheel are what’s causing the trouble:
Your clockspring might be on its way out - this is a common symptom of one that has already failed.

Would that be the “airbag clock spring” that I found on LMR.com??

 

[ttocs]

any reason you mention vac? There is a small plastic ball in the drivers quarter panel that is used to move the actuator for the throttle IIRC. If it is not getting vac it will not work.

 

[Daryl]

any reason you mention vac? There is a small plastic ball in the drivers quarter panel that is used to move the actuator for the throttle IIRC. If it is not getting vac it will not work.

I was spit-balling wondering if it’s activated by vacuum, is all.

 

[Daryl]

Brake lights work, so bulbs are good. And all vacuum lines attached. Any chance that because I no longer have the 3rd brake light since I’ve replaced the stock wing affects the circuit?

I checked Fuse #6 (15amp) which, according to the Owners Manual, is the the Speed Control amp. It’s intact.
So that leaves the clock spring? Which requires the steering wheel, yes? :-(

 

[ttocs]

it is possible, but I bet you could plug that bulb in and leave it dangling in the trunk to test this idea.

 

[07GtS197]

You’re not running led tail lights are you?

 

[Daryl]

You’re not running led tail lights are you?

Yes, I am.

 

[Daryl]

Would that create a problem? I’ve had the LED’s in for a good while now w/o any CC issues.

 

[07GtS197]

Since they weren’t an issue before I don’t see them being an issue now but you never know.

 

[shovel]

Yes. The cruise control uses the filament resistance on taillight bulbs as a check measurement. Probably had incandescent third brake light bulbs before.

 

[Daryl]

So w/o the 3rd brake light, should I go back to incandescents?

 

[ttocs]

The problem IIRC is the way that a diode works and how that effects the led. A diode will only pass current in one direction, which is why an led is polarized is you need the +'s and -'s to match up. If you don't, it will not allow the current to pass backwards and it will look like there is nothing in the socket. A halogen bulb allows current to go in both directions and it can measure the resistance of it to see that there is a bulb there and working. There was someone here that figured it out and put a resistor in somewhere that made it work but I can't find the post now. Hopefully he will chime in.