850 Air Cond./ Not superheat problem

'94 850, standard A/C.

Most times, the A/C works fine, and cools well. Occasionally, the
compressor does not run. When this occurs, the blue indicator on the
dash does not light.

Most often when it fails to work the car has been driven, shut off,
(sometimes for just a minute or two, sometimes for 1/2 hour or so) and
when restarted, the indicator lights for perhaps two seconds, goes
out, and the car will not cool.

Yesterday this occurred, and fiteen minutes later, driving with the
windows down, I felt a blast of cool air, and saw the indicator lit.
The A/C worked well the rest of the way home.

Two things to consider:

1) the superheat switch has been bypassed already

2) The R134 charge is 'normal' per my cheapie suction-side
guage/filler.

I suspect something is getting heat-soaked, and failing, but I don't
know what I might check before sending it to the repair shop.

Any ideas?

Thanks!

 

I suspect something is getting heat-soaked, and failing, but I don't

Magnetic clutch gap too large?

 

How does one check that?

 

with a feeler gauge, can't tell you what the gap should be on the Volvo
but do a search and check that as a starting point.

 

mine had a cold solder joint on the switch board.

 

Would that cause the indicator light5 on the dash to go out though?

Ron/Champ 6

1963 8E5 Champ (Champ 6)
1962 Lark Daytona Convertible (Boomerang)
1995 VW Passat (Vanilla..yuk)
1994 Volvo 850 (Tilley)

 

Hmmm...that could be. I can't really think of why the indicator light
on the dash goes out otherwise.

Ron/Champ 6

1963 8E5 Champ (Champ 6)
1962 Lark Daytona Convertible (Boomerang)
1995 VW Passat (Vanilla..yuk)
1994 Volvo 850 (Tilley)

 

Hey that was close enough to help me find my problem! last 3 times the
A/C acted up, I blasted the switch with a can of air to cool it, and
it started working.

Figuring I had nothing to lose, I carefully disassembled the switch,
and found a burnt contact. I cleaned ther contacts, reassembles it,
and so far, so good, I don't expect it will last too long, but who
knows. At least I've got time to find another switch.

Thanks all!

Ron

Ron/Champ 6

1963 8E5 Champ (Champ 6)
1962 Lark Daytona Convertible (Boomerang)
1995 VW Passat (Vanilla..yuk)
1994 Volvo 850 (Tilley)