So I'm workin' on my 86. It'll be running a carbed vortec 350, and I'm looking at my cooling options. Original wiring is pretty chewed up and hacked. I had a lot of success with running a 4th gen dual fan set up on my last IROC, controlled by a Painless Wiring F5 controller. LOTS of flexibility with that kit, frankly more than I likely needed. Anyhow, finally ended up letting the Holley EFI controll it all, but the F5 kit worked well. Apparently it's not available anymore. Anyone know of a system to do this? I do plan on running AC, although not right away. Lots of missing wires. AC is not on the shortlist, but of course, fans are!

 

bp automotive and current performance both offer standalone kits that just need ground triggers

 

You can make your own fan controller. Here is the basic circuit I use to control my fans, monitor coolant/oil temps, using low cost components


Arduino nano is very cheap. Since this I added 5V power supply external, and transient suppression inductors to the input current, so as not rely on the arduino's internal regulators for reliability.

I use 2-wire 1/8" NPT sensor to measure coolant and oil, ground directly to controller (instead of nearby to sensor grounds like a traditional 1-wire)

This is how you take recorded empirical measurements from the sensors voltage divider to calibrate for temperature range and generate formula



My setup in the lab using a hot-plate to calibrate them


I built a load out board with an LED to directly tell me the temperatures and whether fans are commanded on or off


In the future I plan to add features but I'm pretty happy with it as it is

 

I have Dakota Digital fan controllers in both my Thirdgens. Solved all my control problems and working great for years now.

 

Thanks for the replies guys, I'll look into those kits. KingTA, -that's pretty cool. I think it's a little more than I wanna tackle at the moment, though I appreciate it!

 

As posted above, Dakota Digital has done yeoman service for me.

https://www.dakotadigital.com/pdf/PAC-2750.pdf

https://www.summitracing.com/parts/d...XGeMqKhhTrQup5

I use an aftermarket gauge (sensor in the drivers side cylinder head) and it's output is twinned to the D.D. controller. No more temp sensor on the passenger side needed.

 

It's pretty easy to wire relays up in a hi/lo setup like an LS. You just need 3 cube relays and a switch.I like to use a Volvo dual temp switch......part number 61318361787. It will kick on low speed at 180* and high at 195*. It has a metric thread (14mmx1.5) so you'll also need a threaded adapter. You can buy the pigtail for it but I just use bullet connectors. Here is the wiring diagram. This is an automatic, problem free setup.

 

Lotta mentions of that Dakota Digital part. Found a video on YT of a guy programming. Seems easy. That schematic certainly looks like something I could follow too. The schematic shows pin 33 and 42, which is how it would be wired on an LS PCM, right? -But that's why you mention the volvo switch, right? Since no pcm in my case? When it comes to electronics, I'm that guy that knows just enough to get myself in trouble!!!

Thanks again for the replies.

 

I have a derale single relay fan controller controlling dual LT1 fans on my carb'd vortec 383. Im not running AC but it does have a ground trigger wire for that as well. I'm sure it's just like any other fan controller on the market but it has been simple and trouble free for 7-8 years now

 

Do you have the probe in the radiator or where at on the engine?

 

Yes, the Volvo switch will control the HI and LO......and has a third pin that just goes to ground. The fans will get direct battery current and since the relays are controlled by a SWITCHED on (ignition power), there is a complete cut of power and no fan 'run-on' .