Have a rebuilt unit from Roger with a heavy duty fuse, lately having the unit running full ac or full heat only on level 4. I do not have 1,2,3 speed control to work. Can some members chime in what can caused it to run only on high only....

 

Several possible causes, with the resistance group in the HVAC plenum under the hood being the prime suspect.

Search is your friend - there are many threads on this, with photos, etc.

 

Hello Wally can you direct me to the post ,i searched and seem not able to find it.

 

https://rennlist.com/forums/928-foru...operative.html