Just wondering if anyone has tried this type of controller:
http://www.summitracing.com/parts/rfw-ar99/overview/

It has no sensor that screws into the heads, no probe that sticks in the radiator fins or goes into the rad hose…just a connector that goes under a bolt.

Anyone tried one of these, and how did it work?….reliable or not?

Jegs has one that's very similar. I have dual Derale high flow fans and I currently only have one of the two hooked up with a screw in probe and it's not able or set up to control dual fans.

One fan seems more than enough, but I would like to get both functional.

 

use a flexalite controller. 31165 is what I use. I have used many of them and will continue to. and they can be mounted under the hood. they have gotten a little more expensive. around 160 for it. and it has a soft start.

 

There's no reason why your existing single sensor can't run both fans. The only limitation will be that both fans come on at the same time. If the relay that controls the fan is of sufficient capacity, it's possible to run fans off of the load side of the relay. If the individual fan current is at or near the limit of the relay, then two relays could be used with both being switched by the single sensor. If you want both fans to come on a different temps, or even a manual operation, you could install a second sensor with a different temp rating (in the head or intake manifold) or directly to a toggle switch.
A lot less expensive than the Ron Francis wiring box.

 

I'll look close at those then...Thanks!

After as much as I spent on these fans, expense isn't the biggest issue. Of course there's a limit, but these fans crank out some CFM's! No way I could set them up to start at the same time....the current it takes to start even one is a pretty hefty draw on the alternator/battery till it gets going.

I cringe when I hear guys that don't use any automatic controls and always start fans on toggle switches...it works.... but don't get caught up in the moment and forget! I would however like them start/stop when needed automatically and have the second fan start 10-15 degrees higher than the first if needed. I'd also like the option to manually start a fan should the automatic sensor fail.

Some of the kits come with the wire that hooks into the air conditioning circuit. Since I don't have AC, I'm thinking that could be my wire for a manual override.

 

What I'm saying is that it's possible to build what you're after without having to add a controller. Now that said, of course the controller offers a flexibility of both operation and installation especially if one is intimidated by wiring.
Keep your existing fan which I'm guessing is wired through a relay and controlled via a sensor in the head correct?
Create another circuit wired like the first but through a 2nd sensor which controls a 2nd relay. Select a sensor that has the timing set point you're after. For the manual side, all that's needed is to wire a toggle switch across the sensor so that at the flip of the switch the sensor is bypassed and the circuit completed to ground (just like the sensor). This energizes the relay and turns on the fan.
Easy stuff.
Diagrams available upon request.

 

I had to wire up a new circuit for my fan and had it on a switch for years... Got sick of it and was appalled at how expensive some of these fan kits are. I dont know what threads a lot of the coolant parts are on stock intakes, but I have a Performer RPM and it has a 1/2 NPT port (Two of them), presumably to fit GM factory senders and whatnot, and I threw one of these in it. So far it works fine. Comes on around an indicated 190 (Which is barely below where the 195F thermostat opens) and stays on until 165ish, which is barely below where it normally sits, which is an indicated 170.



But obviously, that's just meant to trigger a relay so you still have to set all that up. But it's about half the price of some of these temperature-triggered fan switch sensors. And I just dont trust the radiator probe types very much. Just doesnt seem like a very good solution to me.

 

Tried a flexolite adjustable controler once, it kept killing my battery as it owuld not shut off often even once the engine was cold as ice.

 

Yes, I've thought about just building my own. I have a few old kits that I'm sure still have good relays. I'll need to see if those relays are rated high enough though…these fans require a 30 amp relay each.
Using a temp warning switch…pretty nifty idea! I suppose it does the same thing any sensor does…grounds and completes the circuit at a certain temp. And you're right…the price of some of these controllers are outrageous.
I probably had one of those things years ago….with the probe that sticks into the rad fins?? And it has a dial to adjust the temp right? Mine worked for about a month, and just flat-out quit turning the fan on (back when I ran one single fan)…

one92rs - I do like the one you posted…looked it up on Summit. I like the soft start feature, but the only thing is, it'll only start both fans at 60% power at the same time…not individually at different temps. I could build my own using two separate sensors….but it would be nice to control both fans with one sensor and have an emergency back-up toggle switch if the sensor ever failed….but this temp warning light deal I could use for one of the fans has me thinking..if I can find one that'll start/stop at the right temps….

 

sorta but you stuck it inside the rad, the wire just bent out and around the flange the rad hose slips onto, and it still sealed just fine.

 

For a basic relay system, the engine switch is the ground trigger. The + trigger should come from a switched power source. That is, hot when the ignition is in the in Run position. Turn off the key = turn off the relay = turn off the fan.

Wired to run with the key off, using the switch in the head, the fan will run and cool the radiator. But, without the pump running to circulate, the engine stays hot... Hence the fan continues to run.

Or something like that.

 

Here’s a circuit to run a high amp fan and will only cost you around $20.00

It’s a totally independent circuit from any stock wiring. I run two, one for each fan. A 14" primary mounted on the inside as a puller that comes on at 190* with a 180* thermostat.

The 16" front pusher is set to go on at 200* as backup.
Both fans are adjustable.
Part #733653

http://www.autozone.com/autozone/par...67187_69565_0_

 

Or you can run this simple circuit using the wire going to the switch in the head as backup and install the circuit above for your primary coming on at a much cooler setting using a 180* thermostat.

 

Here's another option:

https://www.thirdgen.org/forums/cool...electrics.html

JamesC

 

I suppose if you wanted to use a couple a temp switches you could use this set up. a/c on one fan comes on high. temp only both fans on low. a/c and temp both fans on high.

for something easier you use two of the single relay kits and set them to different temp as well.

 

Yes I did not take into consideration the AC but still think they can help a guy out with one fan or two without including the AC.
Lets face it mine are so simple my kid sister could do it.
The price and simplicity is IMO what should make them appealing

 

Thanks for the ideas everyone.

I looked around and found pieces and parts from prior controllers I used in the past. Think I'm just going to put a separate controller together to run the second fan.

I'll set it to kick it in 10 degrees or so higher than the first fan as a back-up.

 

Confused1....didn't you PM me awhile back on a fan control kit? The one I design is automatic and is much more failsafe that anything aftermarket. Let me know I can send you the info again.....it'll make a believer out of you....I've built a lot of kits in the last year.

 

Here's a pic of one of my Motorcraft 2-speed fans now setup to run 3 speeds using my harness.....

 

I have also started outfitting what I refer to as the Mark VIII replacement fan with my 3-speed conversion harness. Here is a side by side comparison of the old and new. Just slightly bigger but can still be trimmed. Since the Mark VIII fans produced by Motorcraft have been discontinued for over a year, this is the most stout single fan you can by OEM or aftermarket. I keep them on hand for local builds and for the street rod guys....the 3-speed harness is really catching on with them around here.

 

Confuzed1 would you mind sharing what Derale fan set you are using? You mentioned it has a lot more capacity than the stock setup. Did you previously have the single or dual fan setup?

 

I had a single electric fan stock. But it just wasn't enough on a hot day idling in traffic . Not helping was the fact I had a 195 degree T-stat and my stock fan temp sensor turned the fan on at 200.....But it was OK till I dropped my 400 small block in.

-Then I decided to put a blower on it. So I got a Griffin 2 core aluminum 31x19 rad, and a bigger single fan for it....but that along with the 195 T-stat still didn't cut it.

So I got a 180 degree T-stat and a 190 degree fan switch...it lasted longer before the temp creeped up in traffic on a hot day. Then one day I was going to a car show up north sitting in a humongous long line of stop and crawl traffic, and my temp got up to 240 degrees!! That's
when I decided to get this Derale dual fan unit with a proper shroud that covers the entire coil.

Now the car stays cool even on the hottest days...so much that I never got around to wiring up the second fan!! I didn't need it!

Honestly the biggest contributor to it running cooler I think is because of the shroud to guide incoming air across the entire radiator more than the high flow fans. This Derale unit was not even close to a bolt in thing. I had to make my own mounting plates, but bolts etc for it to work, but it turned out great I think! I'm not home right now, but I can get you the model number if you really want...but it won't fit a stock ThirdGen radiator.

 

I found it:
26x18 Derale part# 16927 dual fan setup...4000 cfm,

 

Tanks.