I just drove my Jimmy to work today for the first time. It drove much better than I expected, I actually got the truck to use exclusively as a hunting/fishing vehicle. I liked it so much, I plan to drive it to work more after I fix two things that are bugging me.

One is that the driver's side wiper arm fell off, I will deal with that one tomorrow.

The other is that the heat is not very hot. I read around here and think I may have the problem figured out. I have a noise whenever my heat is on coming from the dashboard. When I shut the heat off, the noise is louder, possibly a vacuum leak. When the heat comes out, it doesn't come out very hot at all. I have read about blend doors a little but don't know where to look and how to get to it. Do I have a vacuum leak somewhere? Do I need to disassemble my dash?

 

You may not need to take apart the dash, take out the glovebox to get a little more room and inspect behind there for your vacuum leak. And get on your back on the passenger floor with a flashlight and have a lookieloo up there. I would suspect the leak is causing you to not get enough suction to open the doors on the heater box to allow the hot air through the vents. If you can find the vaccum line the try and locate where the leak is and stick your finger on it and try the vents, this will tell you if thats the problem. Hopefully the leak is where the hose attaches and you can just trim the gnarley end off and stick it back on. The swishing sound is kind of a giveaway of this problem.