Trinary switch install help

[Mayfield]

I have a 85 c10 with factory ac. I swapped a 5.3 4l60e from a 06 silverado last year. Trying to get my ac wrapped up before the summer heat kicks in.

I changed all the components out for new ones, except for the compressor that came with the 5.3. I'm running electric fans, that are pcm controlled. I installed a separate ground signal Relay for the trinary switch to turn on the secondary fan when pressure gets to high.
I mounted the trinary switch on the side of the drier where my binary switch was. I wired the switch up according to VA diagram. Simple & straightforward.

My problem is the switch does not seem to be working properly. The system is charged, compressor kicks in but the fan does not kick on or the compressor did not kick out when pressure got to high, blew a line. So I replaced the line, charged it back up, grounded the fan wires so the fan would run. Ac is nice and cold and pressure is stabilized.

So from what I have read, I can mount this switch on the drier, but that is the low pressure side, it will never reach enough pressure to kick the fan on or the compressor off right?
If this is the case, where are you mounting the trinary switch?
Or, is it possible I just have a bad switch? Any insight would be greatly appreciated.

[Mayfield]

Here's how I wired the switch up
light green- ac on from cab to blk/green
dark green - compressor to blk/ green

Black- ground to blue/blk
green- fan relay to blue/blk

[homemade87]

The trinary has to be on the high side pressure . I had to solder a fitting from a old line to get the trinary mounted . At the time I could not find a fitting to do it .I think there is fittings out there now . Put the old switch back in the drier and factory wire it back up .

If you have the pcm controlling the fans there is nothing special you have to do . There is three wires on the trinary that go to the pcm . This will control the fans . No need for any extra relay for the trianry . If you hook the three wires to the pcm this is all you need . This is how it works from the factory when it comes from gm . Mine works perfect .

Also leave your 85 factory wiring as it was new .All you need to do is hook the a/c request to the compressor from the 85 wiring.

[Mayfield]

So I guess I could put this splicer fitting on my discharge side of the compressor for my trinary switch?

[homemade87]

That is correct , But be carefull of the thread size . That is what I had trouble with . The trinary you need is a metric size . There is some threads in here that has touched on this subject . See if you can fine a couple of them .

[homemade87]

Here you go . Heres a threat back when I was doing mine . The fitting size is 10mmx1.25 female on the trinary . At the bottom of the thread there is a couple links to some fitting that you could use .


http://67-72chevytrucks.com/vboard/s...hlight=trinary