when i push the auto/econ button it wont allow me to turn to auto ,to turn on the a.c. .it will say auto untill i let off the button then turns back to econ. the freon is full...

 

First thing to do is erase all codes related to climate control. If no codes then you have a faulty switch, but thats unlikely. How did you determine the freon is full? Just a 1/4 lb low will disable the compressor and lock out the "auto" mode based on degrees setting selected and ambient air temp.

 

My question would be the same as Carnut. How did you determine that the AC system has the
proper amount of refridgerant? Did you recover and measure the charge amount? If so, did
you evacuate and recharge with the proper amount of refridgerant?

 

Had mine recovered (1.80 lbs) and vacuumed and recharged. Still does not work properly. Will go on auto sometimes only for a few seconds. Other times just as above, goes back to econ as soon as you let go. Even tried changing the relay. For some reason, the parts stores dont stock the clutch cycle switch, I was going to replace that for the heck of it to see if it made a difference.

 

Forgot to mention that it had a small leak at the valve, was replaced prior to vacuum.

 

When you had the system charged, was the A/C system checked for proper operation at
that time? What were the gauge readings at the instant you tried to turn the A/C on?
If the low side gauge dropped to a vacuum, then it would most likely be a blockage in the
system somewhere. Not sure if your car has an expansion valve or an orifice tube to control
the flow of refridgerant, but a blockage will cause the low side to go instantly to a vacuum and the low pressure switch will shut down the A/C since it detects no system pressure. It might
also be a faulty low pressure switch. If the compressor engages for just a second then cuts
out, and the low side goes to a vacuum it is very likely a blockage in the system.
If the clutch does not engage at all, even for a second, then it is more likely an electrical
problem.

 

there may be some misinformation going on here.

1996 models came with Freon-12, today's cars come with R-134 ..
please specify which your car has, converted or not?
one cannot threat both the same.

the technicians often make filling mis-calculations when converting the old to the new.
if the car is converted, listen to your diag center .. if YOUR car computer says LOW, you need more, regardless of the opinion of the AC guy.

there are good reasons for this, but that is a whole tutorial class in itself .. has to do with density and volume thereof.

as carnut stated, it only takes a 4 oz deficiency to shut down the compressor.
one more thing .. erase aLL CODES then reboot the computers .. is something that often resets a lot of things to standard defaults.





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Yes, we need to know type of freon. And is 1.8 lbs. the proper amount listed on the under hood decal? My 91 Allante takes 2.25 lbs to be full and the car is smaller than yours.

 

I thought every car 1995 and later has 134, but mine did come from the factory with 134 not a conversion. It's stated in the owners manual. The system never said low, it only says service a/c system compressor off. The system was charging at the time of service. Not sure about the underhood decal, but the machine said the system was full at 2lbs. So if this is correct, there was not much of a decrease and there was a small leak around the valve which the tech replaced.

 

It needs more 134. Its low.