Help with heater issue in my 2000 Excursion

[guruatbol]

OK, I did some research and found many things that could be wrong so I chose the easiest one to start with.

I changed the Thermostat. Not a hard thing to do and it did not fix the problem.

The problem is that the excursion heats up to temp and just warm air blows out. I opened the glove box door and checked the vacuum pot to see if it is was open and closing the door properly and it is. I pulled the vacuum line and watched the lever move up and down. I reached back behind the plastic pieces where the heater core is and it was darn hot!

I can not find the heater lines, too darn many hoses under there. I wonder if since it is super cold here and a garden hose is a bad idea right now (Making ice) if I should take it to Jiffy lube and have the back flush the heater core?

If I can't diagnose this thing I will be forced to take it to the dealer and in the mean time Amber is freezing he butt off, which is not good with her white blood cell count being down right now.

So, guys if you can help with advice and maybe even pics so I can see what the heck I am doing, I would appreciate it.

Mel

 

[AzPete]

Is the a/c compressor running when you are in heat.......with no defroster selected. If it is, you could have a defective defroster switch.....

 

[guruatbol]

I think I found it. I got frustrated and started to bang on the Vacuum Heater Control Valve that is in line on the heater line. Then further frustrated I took it into town to some hot rod friends of mine at the local Tunex and had them check the cooling system. By the time I got to town the heater was working flawlessly.

We decided that since I checked the blend door and changed the thermostat that the only thing left was the Vacuum control valve under the hood. The fact that I banged on it and it started to work, says that it should probably be replaced.

So tomorrow the part comes in and in about three minutes we will know for sure.

Oh, and the compressor does not come on when the heat is on.

Mel.

 

[joesgt281]

I've had the same prob just this week in the wifes 2000 X.
First drive I froze my tail off.
2nd drive I said screw this, and started trying everything.
The thing that worked was turning on the AC with the heat all the way adjusted to hot (not Max AC).
I don't know why that did it, but from that point on I could get heat via all the other positions.
I think I just finally got a door or the valve to budge.

 

[guruatbol]

It turned out to be the vacuum control valve under the hood. The thermostat was 10 years old or so and was not a bad idea to change it. I checked the old one and it seemed to be bad.

In your case the blend door may have been stuck. Better check the vacuum control valve it is an easy fix and not too expensive if you do it yourself.

Mel

 

[joesgt281]

It turned out to be the vacuum control valve under the hood. The thermostat was 10 years old or so and was not a bad idea to change it. I checked the old one and it seemed to be bad.

In your case the blend door may have been stuck. Better check the vacuum control valve it is an easy fix and not too expensive if you do it yourself.

Mel

thanks, will do