well I got it picked up and its warm but not hot(air) It is coming out of the vents but not as much as the defrost, so Im thinking there is a vacuum leak somewhere but he made sure all were hooked up in the dash, which leads to the question.

If I was to burp the system , how do I go about it, since the system was flushed and the heater core was replaced?

The vacuum line on the passenger side of the firewall that goes to the cruise control, does that have any effect on the hvac system?

Also the hvac control on the dash, the **** that you use to change from hot to cold, seems to bind up in the middle of the red section and then goes all the way?

I have to replace the radio so Im going to be poking around, any tips?

 

The temp control is a cable. Make sure it's free to move easily.

It will burp itself after a few run cycles.

Yes that vacuum line to the cruise, if it leaks you'll have a weaker vacuum at the control head. Check the system at the control head. You have the schematic and can use that to manually operate the doors. Just make up a "jumper" out of vacuum tubing.

 

I'm at a loss, the hvac control unit is switching the vents, you can hear them switching but the "air is lightly coming out of the selected vents, and if you turn it all the way on the dial to red there is no heat at all, it has to be about 1/4 of the way to produce any heat.

Also the temp gauge doesn't get past about half between the first mark and the 210 mark.

I'm thinking I need a new thermostat and can the hvac selector be bad, where all the vacuum lines connect to?

 

Does air blow out the vents/defrost/floor strongly when you move the temp control to cold? That's what I understood from your earlier post.

The blend door, the cable operated one, that control temperature ONLY directs air over the heater core when you turn the **** for heat. It does not control anything else.

How strongly is the fan blowing? Can you hear it change speeds?

 

you can hear the blower and feel it when it is blowing. The strongest air is coming out of the defrost but it does some what come out of the other vents but more so on the cold setting.

I would be happy with just the vents working and some heat.

Is there a temp control sensor?

 

There is no temp sensor for the HVAC.

The control head could be bad but check the vacuum supply first.

There is also a check valve in the HVAC line. It "traps" vacuum in the system so the mode doors don't change position as you drive. It may be restricted. You should feel a very strong vacuum on the output side.

Rent/borrow a vacuum gauge and measure the vacuum at the check valve and at the control head, the black hose.

It really is a very simple system.

I'm beginning to wonder if the fan cage is slipping on the shaft.

Attached is a pic of the check valve, near the brake booster.