HVAC (A/C?) Issue - '92 Taurus
1992 Taurus SHO. I have a mysterious issue with the a/c-heating system.
The heating system has been struggling to get warm, I thought it might be something clogged in the heater hose/pipe system coming from the engine, but the other day - a sunny day so no heat needed - I had pushed the vent button and just out of curiousity I turned the temp up and felt the temp climb as I did this. Turned it back down and the temp went down. Then I pressed Def, and turned the temp up and and it stayed cool!
I do know that the A/C operates a little (off and on in short bursts to keep condensation down) in all positions except Vent. So what part of the system should I check to see what is happening? It seems like the a/c comes on in Def in particular and and then does not cycle off again, keeping the output too cool. I can turn it up to 90 deg. and the Def output still stays cool, in Vent it will turn up.
New heater core
A/C works well when it has to cool the car
all hoses checked for flow
Tested EATC unit, no codes
'89 F250 7.5L, '92 Taurus SHO w/exhaust mods (wow - a Taurus with a clutch!), '93 Taurus GL 3.0 daily driver w/ 305,000 miles and counting (very reliable after rebuilt trans. install).