Where is the pressure switch located for the a/c? The one that keeps the clutch on when the freon is low?

Where is the tempeture switch that turns the extra electric a/c fan on when the engine's warm?

Finaly, where is the tempeture sender for the dash tempeture guage?

Thanks

 

VU, I believe from looking at the manual (87-19) that the only temperature switch is located at the front of expansion valve.
The temperature sender is on the left fender well inside the hose that goes to your alternator shroud.
I didn't see anything marked as a pressure switch.

 

There is a pressure switch in the refergernet system, it cuts out the compressure clutch when the pressure is low, because the low amount of freon would not be able to properly oil the system.

There is a switch, somewhere that cuts the fan on or off when the engine is warm. Not the blower, but the electric fan that sits infrount of the condenser. I know the fan is good, so I'm guessing eighter the thermo switch is bad, or the hood switch is bad.

The one on top of the expansion valve is the Temp II switch. There is one behind the Temp II switch, I can't figure out where it goes. I've been unable to make it effect anything.

The temp sensor in the fender sends a signle to the a/c control head, and controls the tempeture in the passanger compartment. I've got it fixed.

 

Viribus,
The pressure/temperature switch is placed on the A/C filter, it has two functions:
1. Cut off the clutch for the compressor if/when too low cooling media in the A/C system
2. Start the el-fan when the temperature in the condenser get too high - You have another temperature switch for the el-fan placed in the radiator for cooling water - These two switches are connected parallel. I.e. if on of them 'closed'(on) the el-fan will start.

 

The pre-S4 cars have two switches mounted on the A/C receiver/dryer, which is the round can between the radiator and the front bumper.

The switch on the stem that sticks up is the temp switch that operates the auxillary cooling fan. When it gets hot, the fan comes on. It isn't really too effective, as it isn't actually in contact with the freon, but depends upon metallic conduction to transmit the heat to the switch.

The switch down on the side of the can is the freon pressure switch. If the freon pressure gets too low (low freon charge) this switch opens, preventing the compressor clutch from engaging. This switch will normally be closed by freon pressure whether the system is running or not. The lubricating oil circulates witht he freon to some extent, and if there is not enough freon, the compressor will be destroyed. When the system leaks down, this switch will open.

The Temp II switch has nothing to do with the A/C. It is on the top center of the engine, and tells the ignition and injection ECUs the coolant temperature.

The coolant temp switch that turns on the aux cooling fan is located in the forward face of the left radiator tank, near the bottom.

 

Thank you Wally!

Any clues as to what to sensor looking thing behind, and to the right of, the Temp II switch is, and what it does?

Thank you!

 

Sounds like the temp gauge sensor.