I didn't quite understand the FAQ description of the
high port location for the A/C system in my car.
I still have r12, I've got the low port on
the accumulator, but where's the high port?
On the back of the compressor?

Also, the aux cooling fan doesn't go on
when the A/C engages. Where is the relay for
this? The fan turns when I give it power.

Thanks to anyone for info!

Hi, I just went through this about 3 weeks ago. Here's what I learned...

The relay for the electric cooling fan is on the passenger side of the engine, clipped on to the front of the coolant reservoir. It's the same relay as the radio interference suppression relay which is on the drivers side of the engine near the ABS pulsator / brake fluid reservoir. Switch them for diagnostic purposes.

To test the fan circuit which includes the relay, trip the a/c temp sensor which is a 2 pole connector plugging into the back of the passenger side of the radiator. Unplug the connector and join the 2 terminals of the connector wire (not on the rad) with a wire. The electric fan will come on if the circuit is good and the fan motor is working and not seized. If it doesn't work, try again with the RIS relay swapped. If still no, activate the fan motor directly with 12 V at the connector behind the grill on the passenger side. The fan should be turnable by hand if it is not seized.

Good luck.

The high side port is on the back of the compressor and the aux fan does not just come on because you selected the a/c, it is also temperature dependent.