Jimmy Heater

[Vacdaddyt]

Hi everyone, I'm new to this forum and need help fixing a heater problem on my 95 Jimmy. It heats fine but will not shut off and I can't find a wiring diagram of the system to diagnose the electrical. The pot. behind the knob has resistance that changes when turned so I am assuming the problem is else where. What are some of the common problems they have? The doors change when the other knob is turned and the fan and A/C come on but I can't shut the heat off and get cooked while driving. I put a valve in the hose for the summer but now need heat for a MN winter

 

[Molson02536]

Hi everyone, I'm new to this forum and need help fixing a heater problem on my 95 Jimmy. It heats fine but will not shut off and I can't find a wiring diagram of the system to diagnose the electrical. The pot. behind the knob has resistance that changes when turned so I am assuming the problem is else where. What are some of the common problems they have? The doors change when the other knob is turned and the fan and A/C come on but I can't shut the heat off and get cooked while driving. I put a valve in the hose for the summer but now need heat for a MN winter

Your heater and ac actuator for the vent door has gone bad and will need to be replaced. Here is a link so you can visualize where the part is and three are vacuum controlled and the forth is electronic. The temperature door is electronic and controls the flow of air over the heater core. http://i11.photobucket.com/albums/a187/swartlkk/general automotive/97_hvac_sch.gif

A common problem is to find one day when moving the climate control knob on your 95 Jimmy to the cold position and tap the A/C button you get still hot air and hear a *creak* *pop* from under the dash. Well, chances are it's 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.

You will be able to get the one in your 95 Jimmy out by dropping open the glove box and using some small tools. Make sure that you get the right actuator for your Jimmy, there are two types. 1 is for the Auto climate and the other is manual like you have. http://i16.photobucket.com/albums/b40/JoshB_/relay2.jpg

http://img70.imageshack.us/img70/1665/img02053uo.jpg (Auto)
http://i16.photobucket.com/albums/b40/JoshB_/wrongpart.jpg (Manual)

As you can see the difference is in the pin locations for power to activate the actuator.

Good luck and keep us posted.

 

[Vacdaddyt]

heater fix

Well I started in like suggested but found that access through the glove box was not possible. I almost removed the dash to get at the actuator which one of the gears is split open. While under the dash I found a unused remote start device which I removed as it has been starting weird some days. It took about four hours to do, I'm lucky as it is warm out yet for a few days. I used the Jimmy today and it appears to be working good, time will tell if there is anything else going on with the heater. There is still problems with the transmission and the fact that the alternator stopped working and then came back on, still need to pull it to get it checked. So my project will keep me working on it.
Thanks for the info it was a big help.

 

[Vacdaddyt]

Heater fix

I had to remove the dash to get at the part because the glove box could not be separated . The part suggested was broken, as in a gear cracked. I drove it this morning and is seems to be working fine. The dash removal took around four hours to do and while under it I found a remote starter kit that was not being used and the Jimmy was starting weird so I removed it.
Thanks for the info it was appreciated.
Vacdaddyt

 

[Vacdaddyt]

Jimmy heater

I could not get at the recommended part through the glove box. Good idea though. Had to almost remove the dash by pivoting it down and around out of the way. Tight quarters still but simple to get at.The actuator was the problem.
I found a remote starter under the dash that is unused so I removed it and cleaned up the wiring. I ordered a scan tool to figure out some other problems I have yet to address, starting to wish I had put a V8 in instead of replacing the 6

 

[Molson02536]

I could not get at the recommended part through the glove box. Good idea though. Had to almost remove the dash by pivoting it down and around out of the way. Tight quarters still but simple to get at.The actuator was the problem.
I found a remote starter under the dash that is unused so I removed it and cleaned up the wiring. I ordered a scan tool to figure out some other problems I have yet to address, starting to wish I had put a V8 in instead of replacing the 6

Naha, just tune your PCM and make sure you turn down or disable your Torque Management off. This will wake up your 4.3 V6 Vortec , http://www.pcmforless.com/ can do this for you if you don't have scanner to tune your PCM.

Glad you got to the actuator.