850 AC still kinda sucks :P

My air conditioner works occasionally.

After some research on the net, I decided to bypass the "superheat" switch and
recharge the system.

Now, it blows cold but seems to stop now and then - almost like when the
"superheat" switch was still installed - only now the pauses in the generation
of cold air aren't as frequent as when the switch was present.

They also seem to occur only after the A/C has been on for a while (10
minutes+). Shutting the *whole car* off for about 5 minutes will let it start
again - shutting off *only* the A/C for a bit doesn't seem to help at all.

Just to confirm, the "superheat" switch was the white connector running from
the compressor to the car's wiring chassis. I've cut out that switch and
joined those wires directly. The black wires, I've been told, are a diode -
something to protect the radio reception and aren't related to this problem.

I suspect maybe it kicks off due to low pressure but I don't want to overfill
the system for fear of popping something. The gauge/valve setup I have shows
the level to now be acceptable with the car running, A/C on and compressor on.

Ideas?

TIA,
John in NH
~~~
The biggest obstacle on the path to success is the stupidity of others.

My eBay Stuff:
http://tinyurl.com/u0fi

 

Sounds to me like low refrigerant, easy enough to check though, just measure
the voltage across the pressostat, it should be 0 with the system operating
correctly, though when the switch opens up you'll get somewhere around 12v
across the open switch.

 

Subject: Re: 850 AC still kinda sucks

I'll do that - if you can tell me where the pressostat is!

BTW, is this James from RGVAC?


~~~
The biggest obstacle on the path to success is the stupidity of others.

My eBay Stuff:
http://tinyurl.com/u0fi

 

Another problem is that the A/C works fine for a while - typically 30
minutes or more - then cuts out and doesn't work until the car has
cooled off. This is usually caused by the gap in the compressor clutch
being too large, and the magnetic force is not enough to engage the
clutch. (Removing the superheat switch from the circuit as described
above will help this problem, as it will increase the voltage available
to the clutch a small amount.) Others have used the wire going to the
clutch to engage a relay that is fed power directly from the battery.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

I'm willing to give that a go at this point - where would I run the wire TO -
from the 12v on the battery directly to the former superheat switch wire that
goes into the clutch - bypassing the wire from the car's wiring chassis
alltogether?

TIA,
John in NH
~~~
The biggest obstacle on the path to success is the stupidity of others.

My eBay Stuff:
http://tinyurl.com/u0fi

 

It would be like wiring a relay into your headlights, and for the same
reason. You need a standard 4 or 5 pin relay. Run a fused lead
directly from a power source (always on) to terminal 30. Run a wire
from terminal 87 to the connection at the compressor clutch. Connect
the wire that was on the clutch to terminal 86, and ground terminal 85.
If the relay has a fifth terminal, it won't be used. Make sure there's
a fuse between the power source and your relay! Use fairly heavy wire
to minimize any voltage drop, and try to run your wires along existing
harnesses to keep them out of the way of heat and moving parts.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Great - I've got a J relay and seems like that would do the trick!

As soon as the rain lets up, I'll give it a go. Thanx!
~~~
The biggest obstacle on the path to success is the stupidity of others.

My eBay Stuff:
http://tinyurl.com/u0fi