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Discussion Starter #1
Some along the ownership line installed this switch. Now, the Rad fan doesn't come on with the A/C and it looks like there is no low speed. That part isn't a big deal, but I need the A/C to work. Looks to me like I need to take all wire from I1 pin 85 and connect them to pin 85 of the high speed relay?
I'd really rather use the original thermo switch. Is there a way to check it?
 

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You can test radiator thermal switch on the stove in hot water with meter and laser temp gun. I did Quik Silver's yesterday as I thought low side was not working correctly.

As for wiring coming out of it black is ground red is high and white is low.

Looks like all you have to do if I am seeing all wiring correctly in picture is take black and red wire from add on switch and resplice to red and black on radiator switch.

Looks like low speed white wire still hooked up to radiator switch is that correct.

As for low speed not coming on low even if relay I1 and wiring are correctly hooked up, it is because blue and brown wires that are hooked together go to resistor which may not be still in radiator shroud or if so no good so bypassed.

Jump brown and black wire in bottom connector going to white and black wires of rad switch connector and see if low speed relay clicks on (without resistor installed and wire jumped) and fan should run on high speed.

Jump red wire to black wires that are now hooked to add on switch and see if high speed relay click and fan runs on high.

As far as fan coming on with a/c if low speed relay clicks and wires hooked up to it OK then to check fan to run check that trinary switch from your old receiver dryer if none came with new receiver dryer is installed on new one and new one has a valve core in it that is opened by plunger in end of trinary switch.

To see if low speed relay will click and fan run jump brown to black wires at trinary switch to see if I1 relay clicks. That switch if correct configuration to match new receiver dryer port with turn on fan when high side pressure about 200 psi.
 

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Discussion Starter #3 (Edited)
There isn't any low speed resistor in the rad shroud. The wires to the resistor aren't connected, but taped together so they are electrically isolated. I guess all I have to do is connect them together without the resistor. Then I1 will also put the fan on high speed rather than low when the Trinary switch calls for the fan.

I didn't use a new Trinary switch, but reused the one off the old dryer.
 

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If trinary switch working and low speed relay working then yes you have to have those resister wires hooked together to get a/c to turn on fan via LS relay. It will run it on high speed off of LS relay so engine may run a little cooler than normal and A/C blow a little colder.

I use high speed fan override alot on hot days to get a/c cooling faster.
 
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