fan control relay

Made a mistake when unhooking the last car and unplugged my whole fan relay. now I am having problems knowing where it all goes.

I know the red wire is power and plugs into the fan and has a second wire on the same plug to a bolt wire (i.e. alternator power bolt) also that the temp sensor on the radiator has three prongs, there are two settings on it and they are the out side prongs, one is higher and one is 180* that takes a test of the system to hook up properly. The middle prong I am not sure.

I plan on emailing renegade and asking them too since it is theirs. But I figure I might get quicker help here.

I do have anther way to run this setup too. The stand alone engine harness has fan relay primary and fan relay secondary. Would that be a better way to run it and just run off what the head coolant temp says? Is that just a plug in play to the fan or would I have to run it to relays and so forth?

I have no idea about the radiator mechanical fan switch so thats just a guess. If its a true dual setting, the middle would be a common, one outer would be low speed temperature and the other outer would be high speed high temperature setting.

Anyway, you need fused battery power to pin 30 of the relay.
You need power out to fan at pin 87 of the relay.
You need a "Go" signal from the radiator switch at pin 85.
You need ground at pin 86 of the relay.

This much is simple.

You then need to power the radiator fan switch. Youll need fused battery power from the battery to one pin of the switch and once the contact is made at some temperature, it will come out of one of the outer pins of that switch....which one...we dont know. But when it does, it will go to pin 85 of the relay which completes the contact and allows power to finally go from pin 30 to pin 87 and thus the fan.

Think of pin 85 of the relay as a door man at the club. No one goes in until he eats.

I do have anther way to run this setup too. The stand alone engine harness has fan relay primary and fan relay secondary. Would that be a better way to run it and just run off what the head coolant temp says? Is that just a plug in play to the fan or would I have to run it to relays and so forth?

The last time I tried to explain this setup, the guy got irritable ....its pretty involved. Yes, you would need relays and fuses and really nice wiring. Its not hard, its just not easy.

My harness modified by SSP, notes from their instructions. 1998-2002 LS1

--------------------------------

The Dark Blue and Yellow wires are simply a trigger wire for a separate fan relay.
These are ground wires that should be connected to the 86 or 85 terminal of a fan relay that is ground activated.

If only using one fan use the Dark blue wire.

-------------------------------
Seems your wires are a different color.

I know this has been talked about before. I am only running one fan so I only need this one relay.

If my pcm is already wired to accept a relay and according to the instructions provided one wire connects to the 85 and one connects to 85. Where would the other two go then? would they just connect to the the two wires from the fan?

I emailed Speartech too and asked how to hook up his wiring so I know that the computer is turning the fans on at the right time. Thanks for any advice you guys can give

Although you can have several wires from the computer that operate the fans. You should have one wire from the computer that is Fan relay enable. This wire goes to pin 85 of a relay. The relay is grounded at pin 86. Fused +12V goes to pin 30 and power comes out of relay at pin 87 and goes to fan.

Note that in this picture, the pin number at the computer (33 C2) may not be the same as yours.

If my pcm is already wired to accept a relay and according to the instructions provided one wire connects to the 85 and one connects to 85. Where would the other two go then? would they just connect to the the two wires from the fan?

ok that shows how to hook up the relay. That is all i should need. If you look at the picture I posted of my wiring harness and the instructions, it should all be laid out already. So i just connect the relay and fan and it should be good. Thanks 944-lt1

can 86 and 85 be backwards? the wiring that I already was running has the ground on 85 and the input on 86.

This is for an LS1, but this is how I wired mine - gives you the low and high speeds...enjoy!

can 86 and 85 be backwards? the wiring that I already was running has the ground on 85 and the input on 86

Doesnt matter.

ok thanks, The renegade radiator only has one big fan so I dont need a two fan setup. I believe I have this figured out if that is the case with 85 and 86. I will let you know how it goes in a couple days hopefully.

Yeah, 85 and 86 are just the two poles of the coil. It doesnt care which is which.

Looking at Skywalker's diagram and reading SSP's manual, the PCM output on the fan control wires is a GROUND, each wire can go to 85 or 86 as long as the relays are not polarized types. If each control wire connects to pin 85 the pin 86 must be connected to POSITIVE 12 Volts via a fuse. (Or vice versa)This is only the control circuit, a separate +12 Volt fused feed should then be connected to each fan via the normally closed contacts of its relay. The fan is then grounded on one terminal to complete the circuit.


Does anyone know what temps the PCM signals the fans ON?

Looking at Skywalker's diagram and reading SSP's manual, the PCM output on the fan control wires is a GROUND

Thanks for pointing that out! Didnt catch that.

mine has two wires for each fan. They each have a pink wire and then the primary has the drk green and the secondary has the blue. So one would be ground and one would be positive then right? If that would be true then my engine electronics are all grounding through the pcm.

Don't assume that the PCM gives out positives, skywalkers diagram indicates that the two fan outputs on 43 C1 and 28 C2 are GROUNDS

mine has two wires for each fan. They each have a pink wire and then the primary has the drk green and the secondary has the blue. So one would be ground and one would be positive then right? If that would be true then my engine electronics are all grounding through the pcm.

Okay. I see. The aftermarket harness you have is a bit different than a stock harness. Regardless, you only have one fan so that will act as the primary fan. The secondary wires will just be taped up.

So yes, you will hook up the pink wire to pin 86 of a relay and dark green to pin 85. The computer will energize these wires at 180 and allow battery power through the relay to the fan. That should be it.

thank you

I ran my car with the PCM controlling the primary fan and it kicked on at the second notch of the temperature gauge. My PCM is set to do 202 on and 197 off. Thank you for the help guys.