I have a 1998 Chevy S10 Blazer with the computer climate control. I bought it used and one of the problems is the heat is always on. I see under the hood someone has installed a manual shutoff valve in the heater line. I would like to fix it correctly. Any thoughts on where to start? Would it be in the climate controls themselves?

SOURCE: 98 chevy s10 blazer turn signal

Unplug the turn signal relay from the fuse box and start you engine. Does it still make that noise?
If yes... Put the relay back in, that is not the problem.
If No...Then the relay could be bad, replace it!

PLEASE RATE THIS SOLUTION! Thank You Very Much!

SOURCE: heater control 98 chevy s10 blazer

These trucks have a problem where moisture builds up in the heater box then freezes. When this freezes and you change your heater settings it breaks the shaft for the blend door. If this is what happened you should be able to look under the dash above and to the right of the gas pedal and you will see two vaccuum accuators one of them you should be able to wiggle around the linkage if it is broke. To fix this you need to remove the entire dash to get the heater box out which involves discharging the AC and draining the coolant because the heater core and evaporator come out. Please rate.

SOURCE: Climate Control Module Reset

the problem is the blend door actuator. Its is located behind hte glove box. (as far up and to the left as you get get with your hand). The gear inside the motor will crack if it is overdriven. As far as the re calibration, pull the rdo fuse(s). wait about 30 sec. replace fuse(s) turn car to run wait for 40 sec or so. you should be able to get a flashlight and watch the motor turn back and forth. turn key off. you should have heat. if not, pull the motor out. very easy just two screws. open the motor can check large gear for cracks

Jerry Koski

• 443 Answers
• Posted on Jan 25, 2009

SOURCE: 2001 chevy blazer, heater blowing cold air

Pull the stereo back out . they have bumped the vacuum lines that connnect to the heater near the rear of the switch ..

SOURCE: How can I locate the blend door for the heater/defroster

you have a bad control switch.