Tool my 88 300 SE to have freon topped off as it did not seem to blow cold, cool but not cold. Mech put in 134 freon and could not get it to cool down. Told me I needed a Heater diaphram or maybe the heater switch as it was not shutting the heat down and thus heating up the A/C.
Pointed out to a part on the bulkhead passenger side. I don't feel heat on all the time in fact I feel cool air when just on economy vent and blowing outside air in. I am not confident in this diaganosis. I read the post on the electriacl test and lost me, can you help. Thanks, Brian