cant figure this out for the life of me all of the vaccum operated controls work fine all the doors are moving and I can see the arms move on the vaccum controlers, its blowing cold with the temp set to hot, tried swapping out the temp controler and that didnt fix it either , plenty of coolant, new thermostat, new water pump, flushed the heater core with the water hose when I replaced the water pump so its not blocked what else can be causing this.
no heat in my truck;
- Thread starter stoid
- Start date
Molson02536
New member
If the heater hoses are both hot, then there is no issue with your heater core and coolant circulation. The most common issue you have is the heater actuator may have gone bad or is not getting any power to it. Going to guess you have a new Sonoma so here is a link to a 1996 heater system.
Inspect the #34 and all your vacuum lines. Common for the vacuum line from the manifold to the vacuum canister to crack which can cause not enough vacuum to activate the fresh air valve from opening and closing.
Good luck and keep us posted, if you have a different year you can check with the link i gave you for the other years.
http://www.compnine.com/index.php?u...delid=7079&capuid=1&majorgroup=08&grouptype=B
http://www.compnine.com/index.php?u...delid=7079&capuid=1&majorgroup=08&grouptype=B
think its probally this since it controls the temp within the plenum box
ACTUATOR,TEMP VLV(CODE 3982)(ACDelco #15-72971)
my truck is 2000 gmc sonoma sle so I took a look at the new model
looks like I am going to have to take entire dash out to get to it too fun
fun fun....LOL
ACTUATOR,TEMP VLV(CODE 3982)(ACDelco #15-72971)
my truck is 2000 gmc sonoma sle so I took a look at the new model
looks like I am going to have to take entire dash out to get to it too fun
fun fun....LOL
Molson02536
New member
You don't have to remove the dash to get to the blend door motor, the unit that moves a blending door in a duct behind the dash on the passenger side
that moves anywhere between cold and hot, corresponding with your temperature knob.
Your able to get the one in your Sonoma out by dropping open the glove box and using some small tools.
http://i16.photobucket.com/albums/b40/JoshB_/relay2.jpg Eye level looking through the glove compartment area with the glove compartment flipped open and down out of the way. And here the electrical schematic to your Sonoma which is the same as the 98 Blazers. http://i16.photobucket.com/albums/b40/JoshB_/98blazer_Page_1.jpg
1. Disconnect battery cable.
2. Open glove compartment, and lift tab in upper left corner to allow the glove box to swing down completely towards the passenger floorboard.
3. Gently remove the line that enters the "Vac Unit", and then the "Vac Unit" itself by wiggling it upwards off its mount. Once removed gently swing it towards the drivers side and out of your way.
4. You now have access to the Temp Actuator.
5. Carefully remove the electrical connector that feeds the Actuator.
6. Using a 1/4" drive ratchet, and 7/32" socket, remove the two (2) mounting screws. (HELPFUL HINT: For maximum amount of clearance, Keep the ratchet handle facing the drivers side when putting it in place.)
7. There is no screw on the back mounting post, just a pin that holds it steady.
8. Once you've removed the screws you may need to gently pry the Actuator up off the blend door with a screwdriver.
Installation is reverse of the Removal. The Blend Door and Actuator are both keyed, so there's only one way to put it in. Guide the Actuator onto the Door, then re-secure the mounting screws.
Oh and when you order the new actuator, make sure you get the right one. One is for the Auto climate and the other is manual climate control.
Good luck and keep us posted.