Poor heat

dan34yo · Post by **dan34yo** » Sun Oct 02, 2005 4:03 pm

I have a 2000 S10 4WD. Im getting little heat if any. When i do have little heat coming out and when i stop (or idle) it will blow cold air. Changed thermostat and had flushed. I heard the vacum lines behind heater box causes this. Is this true? What could be causing this? Thanks Dan

Post by **HenryJ** » Sun Oct 02, 2005 4:27 pm

Sounds like you have a vacuum leak. Check to see if the gray line behind the glovebox has any vacuum going to it. This line should have vacuum all the time.

Then check the vacuum lines toward the rear of the engine compartment. Look for a loose connection, or cracked / broken lines.

The transfercase switch can be a suspect as well. There is a stickied thread on that one.

BADs Crew · Post by **BADs Crew** » Sun Oct 02, 2005 4:47 pm

Hey Dan34yo. Wecome to the site.

dan34yo · Post by **dan34yo** » Mon Oct 03, 2005 1:24 pm

Others are telling me that its a vacum leak also. Would that cause it to go cold at idle? This is a new one to me. Thanks for the reply's on this one. Im gonna test the vacum lines this week and let ya no. Are these lines off the heater box? Great site you guys got here. Thanks Dan

Post by **HenryJ** » Mon Oct 03, 2005 2:08 pm

dan34yo wrote:...Would that cause it to go cold at idle? ...Are these lines off the heater box?

Lack of vacuum allowing the vacuum pot to default to cold?

They are off of a distribution / control block-

dan34yo · Post by **dan34yo** » Mon Oct 03, 2005 3:52 pm

Very helpful. Seems like there are lot of lines to test. Thank you very much.....Dan