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Looking for Verification that any one of the available relay harness kits will work for my application. Was ready to buy the 2 speed dual fan setup form BP Products, but can't seem to get any technical response from their website and can't find a phone number to call...... Even PM'd a member here that hangs out.....
Have a Ford Contour dual fan assembly going into my LS2 build, harness is being reworked now and PCM will have 2 temp sognal outputs active.
Have OLDAIR Products AC system with trinary switch.
Want to have both fans operate low and high form PCM and both on high when trinary switch requires.
Is there a product I can buy that will do this out of the box, or should I build it myself. Was given a schematic, but would rather buy something already done and use my time elsewhere.
I think the BP Products setup will work but wanted to confirm before ordering.
Got a response from the Entropy guys, they have something similar but it's a bit more expensive. May just buy theirs because they have customer service.
How much current do the fans draw? This is what I did.
I would wire with a bus bar which provides 12v+ to high speed the fan lead.
Wire three relays nearby, each ground triggered from the trinary, low speed and high speeds from the ECM. wire the outputs from the trinary and high speed to the bus bar along with the high speed fan 12v+ input.
Wire the high amp output from the low speed relay to the low speed fan input.
I put a blue sea bus bar (stainless marine) on the lower left corner of the fan shroud I built. It is a great spot for wires to terminate.
Also too a shot of the fused Buseman mini relay box which is mounted nearby.
Joz , Sounds like you are doing the same think I did to my swap . My system was an 04 . I uses the fan you are wanting to use . I used this relay setup from ebay http://www.ebay.com/itm/Electric-Cooling-Hi-Low-Fan-Harness-GM-LS1-LS7-LS9-Engines-/151641155690?hash=item234e84686a . It had the 3 relay set up you will be needing for the H/L speed and it is all fused and had the wiring you will need . It hooks up to the pcm H/L wires . Was and easy install . Also has a cover .
The trinary switch will have to be installed to the high side a/c line . Nothing special on the wiring . The pcm has three trinary wires coming from it that will hook to the trinary . At this point the pcm will do all the work for the a/c fan . It will monitor the trinary and turn on or shut off the fan as needed . And your done . Mine works great . I used http://lt1swap.com for my info . Hope this helps .
If you are getting the harness worked be sure they keep or add these wires for the trinary switch from the pcm .
Last edited by homemade87; Apr 25, 2015 at 08:07 AM.
Homemade, thanks for the link. I'll check that one out too!
First time I've heard mention of using the harness wires with the trinary switch, I'll ask the guy doing the harness for me about that. I just sent it to him the other day.
I just assumed I'd run wires from the trinary to the relay pack based on what I've seen.
The BP setup is a reasonable price, I just hesitate because they make it difficult to contact them.
Appreciate all of the feedback/help. This has been the most confusing part of the build for me so far. The stupid fans......
Homemade, thanks for the link. I'll check that one out too!
First time I've heard mention of using the harness wires with the trinary switch, I'll ask the guy doing the harness for me about that. I just sent it to him the other day.
I just assumed I'd run wires from the trinary to the relay pack based on what I've seen.
The BP setup is a reasonable price, I just hesitate because they make it difficult to contact them.
Appreciate all of the feedback/help. This has been the most confusing part of the build for me so far. The stupid fans......
joz. It is nothing I had dreamed up . It is how Gm does it from the factory . Thats why there is wires in the pcm for it . It works independent of the compressor . The only thing it sees is the pressure . The other nice thing about using the trinany is at highway speeds there is usually enough air to keep the pressure down so the fans will shut off when not needed while cruising .
Last edited by homemade87; Apr 27, 2015 at 01:36 PM.
Originally, I drove the fans from the relay / fuse box for my swap inside the cab. my fan draws 22 amps steady state and more than 30 when it powers up.
Despite running largish wiring (6 gauge) in to the cab to the relay box, the fan coming on still dropped in-cab voltage to -1V. I didn't like this, so I bought that relay box to move the fan and headlight loads to one of the wheel wells. The relay box is fed with its own 6 gauge wire from the alternator lug.
If you put the relay / fuse box / panel in the engine bay, then this might not matter. Otherwise, I might suggest distributing the loads.
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Help verifying fan relay operation 
