Recently, I replaced a seized AC compressor (Mopar C-171) with a new unit.
After a long vacuum and a few days to see if any leaks were present, I
connected the R-12 cannister, purged the hoses, started the engine, and jumped
the low pressure switch. The clutch engaged but both gauges read the same: 61
pounds, the cannister pressure.
There was practically nothing visible in the sight glass (one very small
bubble)and there were no unusual noises from the compressor. I cycled the
clutch several times with the jumper but the pressure reading in both gauges
never changed. I concluded the cylinder head(s) was bad and had another
compressor shipped.
Exactly the same thing happened with the second new compressor...with no
suction, it's impossible to charge the system beyond equalizing pressure with
the canister.
>From experience, I know new parts are seldom to blame and the probability of
>two faulty compressors in a row (one manufactured in 1995 and the second in
>2001) is quite low.
What am I missing?
Phil Brust
Jefferson GA
73 & 82 Imperial
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