2nd Gen Non-Engine/Transmission No Cruise Control/Defroster Only

[JTitone]

While out on the highway over the weekend I turned on the Cruise control and it wouldn't set. Also I noticed that no matter what setting I used for the the heater positions, air would only blow out the defroster. Are these accessories electrically related? Any advice on fixes?



Jim Titone

98 2500, 2wd, ext cab, mbrp exhaust, isspro fuel pressure

 

[c-moor29]

Sounds like a vacuum leak, start at the vac pump and work up

 

[c-moor29]

Both the cruise servo and air duct systems use vacuum to opperate, and when there is no vacuum to the hvac (heat,a/c) system it will default to defrost

 

[ttbird]

check under the driver side battery. A commonly kwown problem area.

 

[fest3er]

• you have a large vacuum leak
• the connector fell off the vacuum pump (a specific example of a large vacuum leak), or
• the connector is pushed onto the vacuum pump too far, blocking the vacuum completely

I did the last to myself once. Pulled it back out to where it should be on the pump and all was well.

 

[Geno's Garage]

Also check the vacuum tee at the cowl panel. I had the rubber boot "relax" and fall off the connector, which caused the same problems. I zip-tied it back on until I could replace it.



Hope this helps.



~Andy

 

[JTitone]

Thanks for quick responses. Sure enough it was a vacuum leak. The vacuum tube was disconnected from the rubber insert. Appears to be what Andy indicated that the boot has relaxed and the tube falls from the connector. This web site is great as you get to learn something new everyday, which is a good thing.



Thanks again, Jim T.