I've got a couple electric fans to cool my engine, and have noticed dropped idles when both fans are on. I don't have A/C, so was wondering if there was a way to modify that idle up setup for my E-fans. I'm not sure how it senses or triggers, so any help anyone could provide would be appreciated. I have found the wires in loom that would hook up to the idle up system, if that helps.

 

22re? --> you'll need Idle-Up valve and vacuum switching valve that's intended for AC. (The dashed black lines on the diagram below).

The idle-up valve runs to a port on the intake manifold and the switching valve is the part you'd wire up.

 

I run one larger fan without any voltage drops. I switched to all LED on my lights except for my headlights... so that might be helping me offset the load. you could also look into fan controllers. at least with them the fans would only run when needed (and turn on the AC idle up if that's how you want to go about it). I'm using one from flex-a-lite.

 

oh, super cool, thanks for the diagram.

I've got two 12" fans, and with only one going, it isn't that much of a drop in idle, and then with both fans on is when I really notice it. I've got the fans hooked up to a switch to run either one or both, and usually turn one on between 160 and 180, and turn both on near 200.

I'm also curious as to how much of a boost the idle gets with the idle up on. If it is too much more than the amount of drain that the E-fans take, then it isn't even worth bothering with.

 

I run a Spal 16''curved blade electric fan with a Centach fan controller which allows me to set at what temp to come on. I also installed a over ride switch so can turn the fan on when I want. When in traffic or come off the high way.
No electrical stain or idle problems. But I do run a Odyssey 1500 battery ,& have a high out put GM 12SI alternator that is 100 amps @ idle & 150 above.

 

The valve on my truck is adjustable to the RPM i wanted.

+1 on the controller. Was that alternator a direct swap? mounts/plugs?

 

I have had multiple bad experiences with multiple controllers by different brands, so that is why I have gone with the switched setup. Even with the controllers I had the idle problems, I'm just going through my wiring harness and cleaning it out, and found the idle up wires and though that I could use them.

I was actually looking into the "direct swap" high output alternators by LCE as a possibility.

 

https://www.centechwire.com/Electronic-Fan-Control-FC-2P.htm

This is the fan controller I use, has nothing to do with idle control.
And the 12SI alternator I got though Quality Power Part # 10150A with plug # W1223 that plugs right into the stock harness. It is polished billet cased was $303.75
I did modify the case & bushing in the lower mount so would line up with my crank pulley ,see photo. But I have a under drive crank pulley so the may not have to be done.

 

What I did

 

why is it that you are running an underdrive?

 

LC Stage 1 Pro Street EFI engine