1995 EATC blowing heat sometimes

[Moes8]

help!

Had the a/c on the other day.nice and cold air coming out,
Suddenly i hear the air coming out change in sound and its full blown heat pouring out.

i start trying all the buttons on the control panel,couldnt stop the heat only was ably to control where it came from,like defrost floor etc,if i switch to vent the air would go to normal outside air,

the tem is set to 60 degrees,

so i get to my stop,shut off car,come out later and a/c is good and cold again.

2 days later driving,same thing hapens,so while driving i do the self diag. on eatc,wait 30 secs,no codes,then turn a/c back on,it blows cold for like 10-15 secs and then heat,

now somedays it works fine all day.others it acts up,
even when heat is coming out the a/c compessor is running.

is this in the EATC control,or something under the dash?

thanks

 

[marked8]

Blend door actuator motor may be going bad, and if it is the symptoms will eventually wind up with either all cold or all hot air and no control. It could also be the control unit, if you can swap in a known working one in to test it would be ideal and would at least narrow it down.