I am having issues with my cruise not working and also sometimes only the DEFROST setting works for th HVAC system.
It just recently got REALLY cold and I'm wondering if there could be water in the vacumn lines messing things up.

In one trip, the cruise started out working, then wouldn't re-engauge when I turned it off and I noticed the vents were stuck on defrost again.
Then about 15 minutes later it went back to working normally again.

Any ideas?

 

I have a 1994 Dodge that does the same thing and it is the worst when cruising down the hiway. I have noticed that if I pump the brakes andsteer the wheel all the way to one side then back to the other it usually fixes it but mine is only with the vent system. My cruise has never been affected but mine quits blowing air all together.

 

Sounds like it could be a problem with the vacuum to me.

 

sounds like vacuum to me too.... could be water, especially if it goes away when warm, but leads you to wonder how water would have gotten in there.....

 

Mine had intermitent vent problems due to a pinhole in the diaphram of the vacuum pod up above the gas pedal. I crawled down there and watched it and the actuating rod would kinda go in and out with some hesitation and if I pushed it in myself it would stay. But I had to do that every time I started the truck. So i went to the junk yard and bought one for a dollar.

 

Sounds like a vacuum leak.
Go buy a hand vacuum pump with gauge from the autoparts and check for leaks. You can test all the vacuum circuits standing in one place at the rear driver's side of the hood.
Most common leak source by far is under the driver's side battery at the cruise control actuator.
Another is a hose accidentally pulled off while changing the fuel filter.

 

I have some oil leaking down by the P/S pump.. Its BLACK, not red. Does that have anything to do with the vacumn pump?

If a line were pulled off, you'd think it would either work or NOT work, not be intermittent.