Darien

Also, if I remove the wires from the thermo switch, will the fan operate if I connect the wires together?

Garth S

Darien,
I think you solved your problem - and then jumped over the answer: above it was stated that the relay checked out OK, but the fan started when a jumper wire was inserted 30 - 87 If the latter happened, the relay is likely toast ( follow the diagnostic tree in Wally's post) - or I've misread it.
The AC/fan relay is XVIII, and is common to the starter, FI, EZX, ... - and the horn at XII.
If you have not yet swapped the relay, please do so with the horn ( least invasive one to pull) It is relay type # 141 951 253 B. - and we'll go from there

Darien

Garth,

I swapped the relay another same part number (reverse lights). The fan still did not come on and the reverse lights worked with the relay I pulled from XVIII.

Garth S

Have you jumpered either of the three triggers for the fan? (listed below) If you do, and the fan energizes - it is working correctly. The most important one for this situation is the rad thermo switch. With the key on, the fan must run - or the relay is not receiving power to pin 86 ( or a ground fault exists on the thermo switch).
As the fan energizes by jumpering 30 to 87 of XVIII, and the relay checks out -
then, I would check the switching side of the XVIII relay socket: switched 12v comes in to pin #86, so with the key on, +12v must be present.
Going through the relay coil and out through pin #85, current will flow to switch the relay on (energizing 87 from 30 to turn the fan on) - if one of the following three closes and completes the circuit to ground: the torque convertor oil temp sensor on autos, the thermo switch in the rad, and/or the freon temp switch.
Get the meter going ... if the jumper wire on the thermo switch does not kick the fan on.

Darien

Thermo Switch officially BAD...

I jumped the wire leads together so I have the fan running with the ignition on.

That should take care of me until I get the clutch fan fixed. Now that I've been driving without it installed, I like the sound and feel of the engine. I may have to check on installing an additional elec fan instead

Thanks all for the help

Garth S

... or possibly it never got hot enough to turn on:it has to get reallllly hot to do so. Whenever you pull it, toss it in a pot of heating water and determine if the switch closes.
In any event, good news.

dr bob

Heads- up!

The thermo switch on my S4 shorted when it got wet. Use appropriate caution when you do the "drop it into hot water" test on the switches and sensors.