Hey guys,

I'm contemplating switching from a single electric fan to a dual electric fan set up. Have any of you done the single electric to dual electric conversion? Was it hard? I was wondering, aside from the obvious of needing new shrouds and mounting brackets, if there are any modifications needed to run the dual fans off the single fan plug that I currently have. Will I have to modify my fan plug? I am hoping that if I simply plug in my fan connector to the new dual fan set up and that maybe both fans will come on when my single fan currently comes on. I have a BeCool aluminum radiator, 160* thermostat and jet fan switch installed (fan currently comes on at 200* and off at 185*). Any help would be greatly appreciated!

 

Could wire in a 2nd relay to switch both fans on at the
same time-sometimes the current surge of both fans
coming on at the same time will cause the ignition to cut
out for an instant,tach to jump,etc.If that happens could
wire the 2nd fan relay to a 2nd slightly higher temp
thermostat to switch on after the first fan,also might wire
both fan motors in paralell and use an aftermarket "soft
start"fan control.For a higher output single electric fan,
the H.D. electric fan used on some '84-86 4cyl fieros
and '86-87 buick grand nationals is very powerfull for an
electric fan-more power than most large aftermarket fans,
including flex-a-lite black magic. 1991-95 3.8L /SHO
ford taurus 2 speed fan is also pretty good.
another possibilty is to install belt drive clutch fan and
shroud from '85 earlier LG4 firebird-that is what i use
on my car,moves more air than a powerful electric and
doesn't use much horsepower if the clutch is working
properly.

 

I converted my 86 from a single fan to a factory dual fan set-up about two years ago. No problems so far. The wiring for the single fan set-up is not heavy enough to pull the load of two fans, however I did not want to deveate from the factory style control. What I did was to take the single fan power wire and use it to switch a 60 amp relay. The 60 amp relay is wired to a 50 amp auto reset breaker, that is wired directly to the postitive side of the battery. The power coming from the 6o amp relay provides power to both electric fans. This way they fans are switched from the A/C pressure switch and controled by the engine temp. When the ignition is off, no power goes to the relay and the fans are off. I also wanted to have the fans switch on at a lower tempature then the factory setting of 230 degrees. I am running a 195 degree thermostat, and have an after market fan switch that triggers at 195 degrees. It powers a 15 amp relay, protected by a 15 amp auto reset circuit breaker pulling power from the ignition switch. The 15 amp relay also provides power to switch the same 60 amp relay to power the fans. This way, if my engine is over 195 degrees, the fans are running. If the A/C is on the fans are running. If the aftermarket system fails, the OEM system will kick in at 230 degrees and run the fans enough to get the car home. My radiator is a 3 flu brass unit, and the car runs a steady 195 drgrees in any kind of driving or weather. The 60 amp relay is available from most RV dealerships for about 15 bucks. It is designed to be a dual battery switch or an auxllary start switch for a motorhome. The switches are made by Tekonsha company, and are very durable. I have had on of these switches in use as an A/C relay for 21 years on an old Dodge truck without any problems.

 

OZZ AC on this site has done that to his car might wanna PM him and talk to him

 

The parts that I bought were a factory dual fan set set-up off of Ebay, abouth $100.00. The Tekonsha 60 amp relay (dual battery switch) was bought from an RV store for $14.99. The aftermarket fan switch and relay comes as a kit, mine came from Summit Automotive, somewhere around $25.00, to $40.00, can't remember exactly. Two automatic reset circuit breakers, one 50 amp, and the other 15 amp, from an automotive parts store like Advance, or Napa. You can substitute a 30 AMP relay for the 50 amp, as the fans pull about 12 amps each running, and that will save you on the wire. If you use the 30 amp breaker, use 10 Gauge wire, and if you use the 50 amp, use 6 guage wire. You will need some assorted wire connectors, and electrical tape to wrap your wire looms, and some nylon tie straps to strap it all down. On the fan supply circuit, I used wire nuts to connect the spliced wires at that feed the fan motors, because they make better contact and have better resistance to thermal breakdown then crimp connectors. You could always solder it, and use shrink wrap tubing to make a neat factory like appearence.