88 Eldorado fault codes

[sonofral]

My Eldo, with 114K, runs fine. However, for some time I've had problems with the AC system.
Currently, I get a message on the DIC "Coolant Fan Fault". This message comes on at the same time as the fan itself turns on, somewhere around 230 degrees. The fan runs fast and smooth, always turns on, and brings the temp back down. So, the fan does not appear to be faulty. What makes this message appear?

Second question:
Reference fault code E040 (Power Steering Pressure Switch) This fault prevents the AC compressor from engaging. Where is the Power Steering Pressure switch located? What has to be removed in order to replace it?

The AC system itself is okay, but these two faults will not let it work.

Please help, anybody?

It's my wife's car; we've had it since new, and really want to keep it.

Thanks.