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Fan Controller Ideas?

Minx on Sun May 19, 2013 11:00 AM User is offlineView users profile

Year: 1993
Make: Ford
Model: Explorer
Engine Size: 4.0
Refrigerant Type: 134

I've had enough of trying to cool this Explorer in the summer. It overheats at idle despite a new (OEM) fan clutch, 11-blade fan, new water pump and hoses, heater core bypass, new radiator, several different coolant formulas, and of course ensuring the condenser is clean. It just can't take North Texas with the AC on.

I'm going with an electric Chevy HHS fan that the Explorer club assures me fits with minor modifications. Do y'all have any suggestions on controllers for it? I'd like something that monitors coolant temp, and kicks on with the AC switch, but (ideally) turns off when I'm moving fast enough. Can't find one for less than $300 so far, and that's way more than my budget can handle.

EDIT: Just occurred to me that a thermostat-controlled switch along with an AC-on switch would do the trick in town, and if I could figure out a way to cut all current to the fan when the auto trans shifts in to OD, that might do the trick.

Edited: Sun May 19, 2013 at 3:49 PM by Minx

emsvitil on Sun May 19, 2013 5:55 PM User is offlineView users profile

I use an adjustable thermostat

adjustable thermostat


2 diodes, and a relay to control my fan on my toyota truck.

Doesn't do anything for speed, but will turn the fan on depending on temperature (you control the temp).


Basically the thermostat and the AC clutch will trip the relay for the fan. Diodes are used so to isolate the controls


+ ------- thermostat ------ diode - >|--------*- relay control-----Ground
AC clutch---------------diode->|---------------/

-------------------------
Ed
SoCal

WyrTwister on Sun May 19, 2013 8:46 PM User is offlineView users profile

Quote
Originally posted by: Minx
I've had enough of trying to cool this Explorer in the summer. It overheats at idle despite a new (OEM) fan clutch, 11-blade fan, new water pump and hoses, heater core bypass, new radiator, several different coolant formulas, and of course ensuring the condenser is clean. It just can't take North Texas with the AC on.



I'm going with an electric Chevy HHS fan that the Explorer club assures me fits with minor modifications. Do y'all have any suggestions on controllers for it? I'd like something that monitors coolant temp, and kicks on with the AC switch, but (ideally) turns off when I'm moving fast enough. Can't find one for less than $300 so far, and that's way more than my budget can handle.



EDIT: Just occurred to me that a thermostat-controlled switch along with an AC-on switch would do the trick in town, and if I could figure out a way to cut all current to the fan when the auto trans shifts in to OD, that might do the trick.




Saw a car show on TV where the electric fan came as a kit , I think ?

A temperature probe was inserted into the fins of the radiator . The " box " had an adjustment to determine when the fan would start and stop .

The mechanic watched the temp gauge on the dash and tweaked the adjustment on the " box " until he got the steady state temo he wanted .

Here is one I found by doing a Google search for automotive electric fan controler .

http://www.summitracing.com/parts/hda-3647?seid=srese1&gclid=COvIt5-6o7cCFYFQ7AodSSsAAw

God bless
Wyr

Toddc72 on Tue May 21, 2013 1:39 AM User is offline

I use that controller on my street/ race car. I use the ac trigger to the unit as the remote turn on by a switch. Been using it for awhile and no issues. Running 2 fans with it. Easy to install.

NickD on Tue May 21, 2013 6:34 AM User is offline

Nothing more efficient than an engine driven fan, electrical fans consume about three times the energy. Driving in city traffic is when you need the most fan loads, and this is when the alternator is least capable of producing that kind of power. Driving 70 mph on the interstate, fan load is minimized due to the windmilling effect.

With problems like this, just dump that fan clutch and find a fixed fan capable of handling the engine speed and really solved problems like yours. Simple and effective and in my own test, didn't make a bit of difference in fuel economy.

Ha, sit in an engineering conference, we have to get better fuel economy, what should we do. Some idiot comes up with picking on all things like that fan that even under worse case conditions can only save about 1/3 HP. Yes, some engineers are idiots. Then severe loads on the alternator, and a bunch of electronics added for fan control even introducing more problems for the consumer. KISS is the word they use for that.

Minx on Tue May 21, 2013 8:17 AM User is offlineView users profile

Quote
Originally posted by: NickD
Nothing more efficient than an engine driven fan, electrical fans consume about three times the energy. Driving in city traffic is when you need the most fan loads, and this is when the alternator is least capable of producing that kind of power. Driving 70 mph on the interstate, fan load is minimized due to the windmilling effect.



With problems like this, just dump that fan clutch and find a fixed fan capable of handling the engine speed and really solved problems like yours. Simple and effective and in my own test, didn't make a bit of difference in fuel economy.



Ha, sit in an engineering conference, we have to get better fuel economy, what should we do. Some idiot comes up with picking on all things like that fan that even under worse case conditions can only save about 1/3 HP. Yes, some engineers are idiots. Then severe loads on the alternator, and a bunch of electronics added for fan control even introducing more problems for the consumer. KISS is the word they use for that.

You know, I have some discussions of this going on at another (Explorer) board and they're saying the same thing. This truck rarely goes on the highway so perhaps I should just lock up the fan clutch or find a direct-drive fan, as you suggest, so as to maximize low-speed airflow.

I'm just tired of messing with all these parts right now and want a final fix.

Edited: Tue May 21, 2013 at 8:23 AM by Minx

Toddc72 on Fri May 24, 2013 12:54 AM User is offline

Nick

Only problem with my setup is that I have the engine pulled back 5 inches in my car. I do not see a super long fan spacer or the idea of having to make a shroud for this setup. Mechanical is better YES, BUT not always an option in every case. Especially since I put the blower on it. There is barely enough room for the fans.

Edited: Fri May 24, 2013 at 12:56 AM by Toddc72

NickD on Fri May 24, 2013 6:52 AM User is offline

It you think you have a problem, try to add an engine driven fan to a FWD vehicle with the engine sitting sideways.

All I could do with these was to mount a thermistor at the mid point of the radiator set to click at 160*F, then redesign the control circuit. Particular with engines using the ETC for fan control. Another stupid idea where in traffic, the engine temperature would vary between 195 tp 235*F resulting in constant thermal cycling in particular on an engine with an aluminum head sitting on a cast iron block. Aluminum expands at a seven times greater rate than cast iron stressing the heck out of it.

With the mid radiator tank thermistor, fan would kick on at 160*F and the thermostat would maintain a constant 195*F for much long engine life and better AC cooling. But should we really have to do this?

Not to displeased with my new Cruze, has a PCM controlled electronic thermostat, maintains a constant 220*F, should learn what you are buying, then maybe they would change.

94RX-7 on Fri May 24, 2013 7:03 AM User is offline

I was researching this very subject to control the Volvo fan I installed on my project truck a while back. That Painless box is a fancy-ass PWM controller. PWM controllers are certainly nice, but not the most economical. The two that I liked the most were:

Dakota Digital's PAC-2750
Delta Current Control's FK-55

What I ended up going with was simply the stock Volvo 2 speed relay connected to a GM temperature switch from a Grand National to trigger HIGH speed. LOW speed will be triggered by a trinary switch on the A/C. Why the GN switch? Because it fit the 3/8 NPT hole that was already in the truck, and it was more or less the temperature range I wanted.

I don't see how electric fans are going to solve your overheating problem, however. A belt driven fan will move more air at anything above idle than an electric fan(s) will. Tell me this....how do you know it is overheating?

Minx on Sat May 25, 2013 8:47 AM User is offlineView users profile

Quote
Originally posted by: 94RX-7I don't see how electric fans are going to solve your overheating problem, however. A belt driven fan will move more air at anything above idle than an electric fan(s) will. Tell me this....how do you know it is overheating?

It has only "overheated" -- by which I mean, misfiring and smelling bad, the sort of symptoms that would make you immediately shut the engine off to prevent further damage -- once on my watch. This was idling with the AC on, summer time (100F), when my attention was diverted.

I replaced the fan clutch after that and got some improvement. Still, it's been several years, and my lovely wife has 3 kids occupying her in the car, and isn't as likely as I am to see the TEMP gauge creeping up toward the red zone. It still does that during extended idle periods in summer with the AC load, and I don't let it go.

The AC loses effectiveness simultaneously, which tells me it's an airflow problem.

94RX-7 on Sat May 25, 2013 2:45 PM User is offline

Quote
Originally posted by: Minx

The AC loses effectiveness simultaneously, which tells me it's an airflow problem.

It might be an airflow problem. It might be the ECU turning the compressor off because the coolant temperature is too high.

If it starts getting too hot, can you hear the mechanical fan louder than normal when the engine RPMs increase?

Minx on Mon May 27, 2013 8:01 AM User is offlineView users profile

Quote
Originally posted by: 94RX-7
Quote
Originally posted by: Minx


The AC loses effectiveness simultaneously, which tells me it's an airflow problem.



It might be an airflow problem. It might be the ECU turning the compressor off because the coolant temperature is too high.



If it starts getting too hot, can you hear the mechanical fan louder than normal when the engine RPMs increase?


When it's hot, I can hear the fan when accelerating from a stop. It's quite loud, then it dies off. That's what keeps me on the fence as to whether it's a weak fan clutch that's the problem.

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