the running sight glass is only one thing, if bubbles show running, its not all the important.
what matters is why the hi/low is tripped.
nothing else. (well if not leaking)
wow you found R12, never seen that in ages... its only sold used, reclaimed here and is like $75 a pound, and rising (punitive taxes)
well great, you a are running spec, refrigerant... great.
well if you over charged it , it will trip.
why not go to and AC shop, and get them to check it with the 2 gage manifold.
then look at the 1991 to 1994 FSM charts for matching (setting) pressure to (outdoor temperature and humidity).. this is the last step in all AC work, getting it right. per the chart.
here is the wrong chart, i dont have the R12 chart.
but shows you how it works.
http://www.fixkick.com/AirCond/r134-1996-chart1w.jpg
the amp has nothing to do with the Hi/low switch, the amp can not command AC "ON", if the Hi/low cuts all power to the relays, ( it wins, and saves the compressor to boot.)
the hi/lo is a fail safe. device.
nothing else matters.
is the switch fibbing or not?, the only way to tell is use the gauges.
my guess is its overcharged,
my wife's car , right now, at ambient 50% hum. + 90F is running 40PSI on the low side. R134a. V6 engine, and does not trip.
sorry i dont have the R12 data.
id get help at an AC shop this is old hat to them.... ,
i just had to buy R22 from my home, dont ask how much, (a fortune) it to is illegal now and taxed to ying-yang.
are you sure its real R12? and not propane or other gasses sold as R12,? (here in usa, there a many hacked R12 clones, and very hard to setup)
whats your low side pressure? running it. with high low bypassed say for 15seconds. (bypass for only short time, and only if you know there is
a full pound in the system.
the samurai spec. i have
ran 18oz . (1993 for example)
the pre 134a ran 21 oz. on sidekicks/trackers/vitaras of same breed.
start with 18 oz and work up.? to 21 oz,
and the generic formula.
Ambient temp X 2.2 = high side pressure
so here is 90f, x2.2 and would be 198psi on the high side.
the correct amount listed on some pages is 21 oz. of R12. (before R134 changed it)
so put in the R12 , from total vacuum. say 15oz, (about)
then as you near the 28psi the HI/log closes. and the clutch pulls in and compressor wakes up.
then use the charts. to top off...
that is what the charts are for , the fine tuning.
only other way is :
on the generic sites (a/c.) you most know the total volume of the system to do their math, and that is not known.
the 21 oz. is by weight, not volume of r12 can. yes, tricky and is sold commercially by weight. in fact the jokers scaled my F22 can before and after i was charged up)
liquid gold here it is.....
be very sure the system has say at least 15oz of R12 and oil to spec.
before hot wiring (jumping) the hi/low switch.
and do so for short time. just long enough to glance at gauge.
or set up, start engine.
and jump it. 15seconds.
got 20 or more PSI? on the low side. if not?, cut the jump and add more... repeat.
you need the over 30psi for the Hi/low to hold in, then when it does, the compressor runs by self. (amp happy? sure)
then top of fto the charts. (using your local radio station temp and humidity , live)
or this.
http://www.wunderground.com
type in your town and bingo, local ambient.
good luck !!!
keep in mind the system hates water, in the loop,
the vacuum pull , gets out all water, and air is full of it.
im no loop expert. (i can only tell you why the logic fails or why the hi/low fails. tuning the loop takes, serious art now, and skill.... due to.....
and with the reclaimed R12, gee what do you get with reclaimed, well, some R12, propane, some R134 and god knows what.?
and just where are the tables for R12, "who knows what" , same answer , nobody knows... call it R(HKW) or R666 ?
crossing fingers that your Canada R12 is pure, from Dow Chem.
what matters is why the hi/low is tripped.
nothing else. (well if not leaking)
wow you found R12, never seen that in ages... its only sold used, reclaimed here and is like $75 a pound, and rising (punitive taxes)
well great, you a are running spec, refrigerant... great.
well if you over charged it , it will trip.
why not go to and AC shop, and get them to check it with the 2 gage manifold.
then look at the 1991 to 1994 FSM charts for matching (setting) pressure to (outdoor temperature and humidity).. this is the last step in all AC work, getting it right. per the chart.
here is the wrong chart, i dont have the R12 chart.
but shows you how it works.
http://www.fixkick.com/AirCond/r134-1996-chart1w.jpg
the amp has nothing to do with the Hi/low switch, the amp can not command AC "ON", if the Hi/low cuts all power to the relays, ( it wins, and saves the compressor to boot.)
the hi/lo is a fail safe. device.
nothing else matters.
is the switch fibbing or not?, the only way to tell is use the gauges.
my guess is its overcharged,
my wife's car , right now, at ambient 50% hum. + 90F is running 40PSI on the low side. R134a. V6 engine, and does not trip.
sorry i dont have the R12 data.
id get help at an AC shop this is old hat to them.... ,
i just had to buy R22 from my home, dont ask how much, (a fortune) it to is illegal now and taxed to ying-yang.
are you sure its real R12? and not propane or other gasses sold as R12,? (here in usa, there a many hacked R12 clones, and very hard to setup)
whats your low side pressure? running it. with high low bypassed say for 15seconds. (bypass for only short time, and only if you know there is
a full pound in the system.
the samurai spec. i have
ran 18oz . (1993 for example)
the pre 134a ran 21 oz. on sidekicks/trackers/vitaras of same breed.
start with 18 oz and work up.? to 21 oz,
and the generic formula.
Ambient temp X 2.2 = high side pressure
so here is 90f, x2.2 and would be 198psi on the high side.
the correct amount listed on some pages is 21 oz. of R12. (before R134 changed it)
so put in the R12 , from total vacuum. say 15oz, (about)
then as you near the 28psi the HI/log closes. and the clutch pulls in and compressor wakes up.
then use the charts. to top off...
that is what the charts are for , the fine tuning.
only other way is :
on the generic sites (a/c.) you most know the total volume of the system to do their math, and that is not known.
the 21 oz. is by weight, not volume of r12 can. yes, tricky and is sold commercially by weight. in fact the jokers scaled my F22 can before and after i was charged up)
liquid gold here it is.....
be very sure the system has say at least 15oz of R12 and oil to spec.
before hot wiring (jumping) the hi/low switch.
and do so for short time. just long enough to glance at gauge.
or set up, start engine.
and jump it. 15seconds.
got 20 or more PSI? on the low side. if not?, cut the jump and add more... repeat.
you need the over 30psi for the Hi/low to hold in, then when it does, the compressor runs by self. (amp happy? sure)
then top of fto the charts. (using your local radio station temp and humidity , live)
or this.
http://www.wunderground.com
type in your town and bingo, local ambient.
good luck !!!
keep in mind the system hates water, in the loop,
the vacuum pull , gets out all water, and air is full of it.
im no loop expert. (i can only tell you why the logic fails or why the hi/low fails. tuning the loop takes, serious art now, and skill.... due to.....
and with the reclaimed R12, gee what do you get with reclaimed, well, some R12, propane, some R134 and god knows what.?
and just where are the tables for R12, "who knows what" , same answer , nobody knows... call it R(HKW) or R666 ?
crossing fingers that your Canada R12 is pure, from Dow Chem.
http://www.fixkick.com