1995 Monte Carlo No Heat

[pwmin]

I used to have heat, but it won't switch from cold anymore.  Started intermittent, but now it's permanent.  I'm thinking it's the blend door actuator.  Any other things it could be besides a vacuum line?  Is this the correct one and where is it located?  Is it the one to the left of the glove box? I've replaced plenty on GMT800s and 2nd Gen W's.

https://www.rockauto.com/en/moreinfo.php?pk=85484&cc=1056428&pt=10721&jsn=667&_nck=S9TpZc1fXxr7Xa7yUkP8%2BeVHrLluc6vJvrD2O9wgZs5RffpngaQG8wezeYP9fpHdOn5lato7smAZZ6tajgo%2ByAcvGnlbm7gWQ1k3lUBRwWeEUtTccaRuCow%2FiASFJvfjkuykQzPMOtbz3c9d3dg2Jwa2GXon2nPW456wgqIX0aMxZ6Nc%2B76i78Di5iBUsi33RWIvDIg08cGCapSM%2FcfHfndGUOG3yYrbav%2FLKA2juWh%2FAYpE3fgdKRVTmgyRZ5Lr3LTjS8N8aR7BaphHG3pne8D1vTbj5ru9dMoXwBdelgZ7crUL5rYxZZQYphmOI%2BTe&_nck=S9TpZc1fXxr7Xa7yUkP8%2BeVHrLluc6vJvrD2O9wgZs5RffpngaQG8wezeYP9fpHdOn5lato7smAZZ6tajgo%2ByAcvGnlbm7gWQ1k3lUBRwWeEUtTccaRuCow%2FiASFJvfjkuykQzPMOtbz3c9d3dg2Jwa2GXon2nPW456wgqIX0aMxZ6Nc%2B76i78Di5iBUsi33RWIvDIg08cGCapSM%2FcfHfndGUOG3yYrbav%2FLKA2juWh%2FAYpE3fgdKRVTmgyRZ5Lr3LTjS8N8aR7BaphHG3pne8D1vTbj5ru9dMoXwBdelgZ7crUL5rYxZZQYphmOI%2BTe

Edited November 26 by pwmin

[pwmin]

and now it's working again.  I ordered the one I linked to, so I'll probably just replace it anyway.

[pwmin]

Well, now it's only blowing out of the defrost.  Fan is working, but I'm not sure about the heat/cold right at this moment.

[55trucker]

Well, defrost is the default direction for all optional failures, as for the heat can you get your hands around the inlet or outlet core piping to feel what the coolant temp is?

if the blend door is stuck closed so the inlet air bypasses the core that would deliver what you're presently getting.

One can see the actuators if you pull off the instrument panel cover, they are right behind where the glove box is.

 

Edited 6 hours ago by 55trucker

[pwmin]

2 hours ago, 55trucker said:

Well, defrost is the default direction for all optional failures, as for the heat can you get your hands around the inlet or outlet core piping to feel what the coolant temp is?

if the blend door is stuck closed so the inlet air bypasses the core that would deliver what you're presently getting.

One can see the actuators if you pull off the instrument panel cover, they are right behind where the glove box is.

 

Sweet, thanks.  I'll pull the cover off and check and see if I can feel or laser temp the piping.

[55trucker]

You should be able to get at both sides of the heater core...return is at the front of the engine, that long steel piping that follows along the right side frame rail that sweeps upwards to the coolant pump manifold, the inlet side is right beside the brake vacuum booster, a short hose that  passes overtop of the master cyl reservoir slipping over the steel supply pipe from the bottom of the thermostat housing. 

[ron350]

 Have you checked the vacuum line that supplys vacuum to the HVAC vacuum switch behind the glove box?

 On my 96 Regal acid from the battery ate the plastic vacuum line that runs under the battery tray to the vacuum ball.

 The vacuum ball is under the battery tray up inside the fender. The plastic line that connects the vacuum ball to the vacuum "T" breaks and this causes all HVAC air to blow out of the defrost vents.

When this happened to me I replaced the brittle plastic vacuum line under the battery tray with rubber vacuum hose.

Edited 55 minutes ago by ron350

[pwmin]

17 minutes ago, ron350 said:

 Have you checked the vacuum line that supplys vacuum to the HVAC vacuum switch behind the glove box?

 On my 96 Regal acid from the battery ate the plastic vacuum line that runs under the battery tray to the vacuum ball.

 The vacuum ball is under the battery tray up inside the fender. The plastic line that connects the vacuum ball to the vacuum "T" breaks and this causes all HVAC air to blow out of the defrost vents.

When this happened to me I replaced the brittle plastic vacuum line under the battery tray with rubber vacuum hose.

I redid all the vacuum lines a little while ago because the turbo PCV wasn't set up properly.  Maybe I messed something up.  I think the vacuum ball is long gone due to packaging issues, but it was working at one time.