Taurus Fan and 5.0 Ex. Radiator on '99 4.0L

[JoshT]

Once I'm done with my engine rebuild I plan to install an electric fan. Hearing all the reviews over the years I plan to get a 2-speed Taurus fan and cut the shroud down to fit inside a stock Ranger or Explorer (depends on radiator) shroud. The issue is that I don't know how to run it. I could put it on switches, but I'd rather keep it automatic, with maybe a master kill switch in case I ever need to prevent it from coming on. Main two fan controllers I seem to see are the Dakota Digital controller, and one modded to work from a Volvo. The Volvo unit would be a hard sale since I don't really have any parts yards to get the needed items from. The Dakota Digital is expensive, but looks like a good option just not sure how to wire it or what sensors it would need. Any recommendations on a fan controller, either off the shelf or DIY/modified?

Last year I swapped the stock radiator in my '99 4.0L Ranger for the dual core 5.0L Explorer radiator from my donor for the 86 motor swap. Made sense since at the time, since I had the radiator out and the dual core was sitting there. About to pull the motor and am thinking I might replace the entire cooling system with the exception of the heater core (not leaking and a bitch to change). Should I go back with a stock single core replacement, or do I get another dual core radiator?

 

[RangerSVT]

Go with the dual core...
the volvo switch is only 5 wires, one power in, two powers out, one low, one high, and two ground signal wires, which attach to a temp sending unit...

SVT

 

[JoshT]

Bumpin this rather than starting a new thread. Got a Taurus fan and spare motor from the yard last week. Also got a Volvo relay, but haven't decided if I am going to use it or another relay set-up I found (mor on that if I use it). Now I'm trying to figure out switches for it, and want to retain use of both speeds.

I've alredy decided to get a hose adapter to put the thermal switch(es) in the upper rad hose. Trying to figure out what switches to use. I know a lot of people like to use the BMW dual switch that is rated for 195 low and ~210 high. It has been suggested to me that since these trucks use a 195 degree t-stat that the low temp is too low, and that the fan will be running all the time. Anyone got experience using this switch in a 4.0L Ranger? Any suggestions on switches, can be single temp or dual temp?

Also want to do some manual override switches in the cab. Would like to have 3 switches max, but would prefer two. My thought is a main on/on/off switch with the positions being on/auto/off. On position will power/ground main power elay for fan and a second rocker switch that is on/on with it being wired for high/low to over ride the thermal switch. Auto is just that control relay and thermal switches doing the work, will power/ground the main power relay and the second switch is dead. Off will be master off, kills power or ground to main fan relay. Any thoughts on this wiring idea, I can try to draw a diagram this weekend if that will help explain what I am thinking.

 

[RangerSVT]

You only need one 3 way switch, center off, up on (manual hi), down on (auto sensor). A second switch could be used for master on/off...

SVT

 

[RonD]

Use the Grounds to control the relays, same as temp sensor does.
So the switch on the dash is connecting and disconnecting the Grounds for the relays, it is the same wiring as using 12v side, actually one less wire since you can ground the switch inside the cab, but in the event of a short worst case is that the fan is on while key is on.
If using 12v and there is a switch short, worst case is no fan at all.

 

[JoshT]

Using the grounds is what was what I was thinking. I just hadn't sat down and looked at the wiring long enough to be sure.

What I really got to figure out is the thermal switch temps. If I can't get those right none of this will work.

 

[RangerSVT]

You can either use two single temp senders or the bmw. I switched the thermostat from 195 to a 180...

SVT

 

[JoshT]

Don't think I want to drop down to a 180 t-stat. Was just looking on Rock Auto and noticed that the motorcraft t-stat listed for it is 190°, so I may get one of those for it.

Did find a VW switch rated at 200 low and 215 high. Might be a better option for me than the 195/210 BMW switch.

 

[RonD]

Yes, don't lower the operating temp, you get better MPG and cleaner oil between 195 to 220degF.

200/215degF unit should be fine

 

[JoshT]

Might actually be okay with the BMW switch and stock thermostat. Picked up a remote thermometer today and did some checking. The spot i will likely put the switch is right where the upper rad hose crosses under the air intake duct. Checkdd temps there and at the t-stat outlet at idle after warming up and driving a few miles. Temps on the thermometer were 5-10 degrees cooler where I plan to put the switch. Will check again tonight after drive home from work.