Finally, Got the Fans Automated!

[farmtruc]

I finally got my fans hooked up to the pcm!!!
After a long time of dealing with the toggle switch and keeping an eye on the temp gauge in traffic, the pcm does it for me. Man, what a relief. It's so nice to have it automated, ok enuff of that, on to the tech stuff.

I got most of my parts from partsexpress.com. They have almost everything you need for electronics and stuff. The relays were less than 2$ each. The wiring i got from NAPA, and the connectors same place.
For those of you wanting to do this to the truck pcm, it also supports it, it's the same as the z28. I'll find the pin if anyone cares to know.
I used some circuit breakers instead of fuses, i may fuse it later, but it's safe for now.

I set the pcm to turn the fans on at 185, and turn them off at 179. On the highway I run about 176-178 and at idle , in the hot summer time, i run about 181 with the fans on. So, the fans will never shut off in traffic, but as soon as i get going and moving my temp will obviously drop and they will go off. I'll tweak it later, but i think that's the perfect setting for my app.



later,

allen

[Sleeper]

nice i was wondering about the PCM controlling the fans the other day.

Brandon

[GMCwantsLS1]

Now it's time for AC!!!

[Domeskilla]

:lmao: He can make me a bracket when i swap, since he is doing his.

[99 red silver]

Hey Allen I need to know how to do this. I am going to get parts installed starting Tuesday. I will get some pictures of the install. I will mail you the instructions. I have an 282 Flexlite fan to install.

[farmtruc]

I drew up my wiring schematic and now it's on the Articles section at ls1truck.com. It's really self explanatory. The only problem I see you having is that the truck harness does not have wiring for the fans. Once you trace down the pin you need to use you will need to install a wire and crimp the right end onto it so that you can slide the wire into the pcm connector. To do I would: Find one of the sensors that aren't being used. I know there are a couple or at least one sensor on the passenger side that is not being used on the trucks. Follow that to the pcm ( i think it goes there) and pull that wire out. Now you don't have to make one, just disconnect your battery and pull the pcm connectors off, remove those grey covers that are ontop of the connectors, remove the red or blue clear connectors that are on the inside of the pcm connector. Now you can pull that plastic tab out and pull that wire from the pcm that is connected to the unused sensor, i hope this is making sense lol.

this pin will be the activate pin for the relay. It grounds the wire when the pcm hits a determined or set temp.
the rest of the wiring is on the site and is pretty easy to read.

How are you going to set your fan temps, if i remember right, they are set way high on the trucks becuase they don't use fans. You'll need to edit that in order for the fans to come on by the pcm.

Let me know, i'll help out as much as i can.



later,

allen

[99 red silver]

Thanks Allen got them printed and I will let you know how it goes.

[Hit Man X]

Holy shit! That is awesome.

I run the LS1 fans so...
Now answer me this: can you have one fan come on before the other? For instance one on at 185* and the other at 195*?

Or is it better for both to come on and cool fast?

[farmtruc]

Ya, you can have one or two come on. I chose two becuase one fan will cool the engine so fast that the second fan wouldn't come on anyway, one fan is sufficient for my app.

the fans do pull the volt gauage down when they come on and it shoots back up , no biggy, but i may have one fan come on at 185 and the other 186 just to cut down on the amount of drain i have when they both come on at the same time.

other than that they work awesome and i would def. recommend it.

i have the 01 z28 pcm but the trucks pcm supports it too.


later,

allen

[Hit Man X]

I was thinking on fan #1 on at 185* off at 178* and fan #2 on at 190* off at 183*.

How would I go about wiring up two fans? Is there another pin to use?

From that site you stated, what relays do I need? 30A or 40A?

Thanks!