Well, curious to try this because I'm needing to install an aux fan remote switch and my AC isn't working atm- so this could safe me the hassle.

Similar jump procedure as the low pressure switch?
I wonder if this trick would work if the low pressure switch is faulty, which I suspect in mine. Or that
you'd need to jump both high and low switches to make your suggestion work?

Edit: I jumped my Low pressure switch in the past which made the compressor come on, so that would not be desired if I'd only wan the aux fan to come on. So I take it only jump the high pressure switch?

 

Yes, my system has no compressor or condenser, and i removed the black hoses also. Just the fan side of the high pressure switch is jumped and now the fan turns on when any AC mode is selected. The big silver can at the firewall is still there, with the low pressure switch still connected but I don't think that matters

 

Can you post a pic (as you mentioned) if which two pins to jump? Or does it work the same as jumping the Low Pressure Switch connector?

 

The high pressure switch has 4 slots ...two for fan on and two for compressor clutch off. I will post a picture later today

 

So the high press connector has 4 wires ...when held in correct orientation the fan side is a lt green and skin /peach color ...the clutch disconnect is a lt green and blue/pink ...so jumper out the green and peach...fan should turn on when any ac mode is selected

 

Brilliant- will have a look tomorrow at this because I couldn't find the HPS in my RHD in the semi dark 😆

 

The connector cable is not that long and should be fairly close to the back of the compressor regardless of the drive side

 

Ok two hard-lines running from the back of the compressor. One bend to the back and ends near the accumulator where the LPS is. The other bend forward and has this switch with connector on it, which I take is the HPS. It only has two wires, the ones I cleaned a bit for the pic. Maybe difference between the years? Or RHD (however wiring appears same two leads on the HPS in the FSM)? The fsm wasnt much help..maybe I'm missing something but that could only be the HPS...

 

Think I worked it out, downloaded the 2001 FSM.
The PCM has a separate "radiator fan request" in the '01, the 97 doesn't. Bummer.
Diagrams below- 01 on top, 97 below that. Click pics for focused view.

Ps: how many AC low/high pressure switches does the 2001 have!?

 

Fear not...the fan comes on anytime the ac mode is selected and the clutch engages if the low pressure switch shows continuity on pre 2000. If its not working remove low press switch and jump the 2 pins...that will energize the clutch and turn on fan...then remove high pressure switch connector and jumper those 2 pins. It will sense high pressure and disengage the ac clutch but keep fan running to cool down the freon anytime ac mode is selected. If still no fan then just disconnect the high pressure switch and don't jumper...im not sure if your high pressure switch makes continuity at high pressure or breaks continuity at high pressure. One way to tell is read the high pressure switch itself with ac not running. If its open or very high resistance then the switch makes continuity at high pressure and you need to jumper the connector. If the switch shows continuity then just leave it unplugged and the fan should run without the compressor engaging with ac mode selected...the diagram for the 2001 shows 2 high pressure switches only because one is for the 4.0 and the other is for the 2.5

 

Makes sense to try and check that.

When I jumpered my LPS (low) weeks ago to try and chase the reason my AC stopped working (still not working btw) , I remember the AC clutch would engage but the fan didn't at that time, I think. I'm not sure if it would work therefore, but you're explanation does makes sense.

Once I have a day off, I'm going to try this because it would be easier to use the pre-existent selector rather than installing a whole separate aux fan remote switch.

 

Silly question, but the fan does work if you remove the connector on thermostat temp sensor?

 

Yep checked that recently and it did

 

Ok at least we know fan and relay work...now that I know your exact model, will check wiring Prints to see if we have missed something... if mine works with no compressor or lines...we should be able to Make yours work too.

 

I'll check again to see if my fan comes on when the LPS is jumped and the clutch engages. If the clutch engages but the fan doesn't come on, I have an issue...