Cruise control: clutch switch or CC computer?

[shagrath]

Ok here we go. The wife's cruise control is not working right. When you engage it, the brake light on the check panel comes on, and I have to press test to stop the flash on the cluster.

After a few minutes or 20 of CC operation, it just cuts off on it's own and does not come on again unless you turn the car off and restart.

What I have done:
-replaced the cluster (it needed it anyway for other issues, but this is a known good one with good effects on CC)
-adjusted the clutch switch so the pedal can fully push it in
-verified the CC actuator isn't making crazy noise

What I ssuspect at this point:
-faulty clutch switch
-CC computer

Any ideas, good sirs?

[Sterling]

Why isn't your brake light switch on that list?

[shagrath]

Yeah I didn't think about that until just a few minutes ago while talking to my wife on the phone about it. Our van had a similar issue and the brake switch adjustment helped.

The lit brake light warning on the check panel might be an indicator for this as well...

[waynet1]

I'm going to second the brake light circuit. Clean up all brake light connections in the trunk. CC senses ground from back there, believe it or not. Don’t forget about the third brake light as well.
I am emailing you a schematic of the CC. Can’t remember where I got it from, may have been a link from someone here over the years. May be of some help.
CC is on the top of the list as far as what MUST work on my car. I use it all the time.

[shagrath]

Got it Wayne! You are awesome.

Fortunately Lin's car doesn't have a 3rd light so that's one less thing to check. I will check the grounds out when it's not raining ass out there.

[waynet1]

Any joy with this Matt ?

[Jeremy]

Got it Wayne! You are awesome.

Fortunately Lin's car doesn't have a 3rd light so that's one less thing to check. I will check the grounds out when it's not raining ass out there.

Cruise control, like the check light, isn't affected by the third brake light. It's the main lights you need to be concerned with. Check and clean all the grounds in the trunk. Clean the sockets, the receptacles, and make sure you're using quality bulbs. Cheap bulbs are known to cause brake check circuit issues, and by extension, cruise control issues.

If you've got water issues in the trunk, tackle that first.

[waynet1]

Got it Wayne! You are awesome.

Fortunately Lin's car doesn't have a 3rd light so that's one less thing to check. I will check the grounds out when it's not raining ass out there.

Cruise control, like the check light, isn't affected by the third brake light. It's the main lights you need to be concerned with. Check and clean all the grounds in the trunk. Clean the sockets, the receptacles, and make sure you're using quality bulbs. Cheap bulbs are known to cause brake check circuit issues, and by extension, cruise control issues.

If you've got water issues in the trunk, tackle that first.

Third brake light is most definitely in the check light circut.
But since they don't have one, it's moot in this case.

[Jeremy]

Third brake light is most definitely in the check light circuit.

Not according what I've heard over the years, but I never took the time to confirm. You sure about that?

[waynet1]

Third brake light is most definitely in the check light circuit.

Not according what I've heard over the years, but I never took the time to confirm. You sure about that?

Yea, it shows in the schematic.
I could tell you a long, funny story about that, but you can probably guess.
I also, before I posted , took the bulb out of it to make sure. Sure enough, no bulb in third light=check light will not extinguish with pedal press.

[shagrath]

Ill be working on it tonight.

[mooseheadm5]

ETK confirms that there is a check relay in the CHMSL that is separate from the regular rear stop light check box, but all are connected to the check panel via the same wire.