Isaacs

Hi all

I'm stepping into a mess with my dads 1990 3.0 pickup RV that had a burnt out electric puller fan From what I have read the standard pickup comes with a mechanical fan off the water pump and that is usually the best cooling option but im not sure if that is still the case on one that's been converted to an RV. I was told the fan would run all the time so that would explain why it burnt out. The relay is wired up to a black wire with a yellow trace and silver dots in the fuse box by the battery. That seems to always have 12 volts so that explains why it was always running.

Ultimately I would like to have the fan only kick on when the coolant temperature gets too high. I have seen others have put toggle switches to control the fan but I would rather not have to have my dad worry about that. Can I tap into the coolant temp switch so that the fan will only come on when it gets hot? Or should I just convert it back to a mechanical fan?

Thanks in advance for any assistance.

wyoming9

iTrader: (1)

Go Back to the Stock fan set up which will cool much better then Electric 98% of the time.

unless there is a Physical reason the mechanical fan will not fit.

Did the Engine overheat head gaskets can be fun?? i made good money changing heads and head gaskets when electric fans quit.

atcfixer

iTrader: (1)

If you keep with the electric fan, hopefully it pulls a lot of air, since it wasn't designed for the toyota, you'd want something that's overkill to be sure. For wiring, best case would be to tap into the ignition wires (power when key on), run the power through a temp switch (physically installed in the coolant path to sense temp), then back to a relay. The actual switching side of the relay would be between battery and fan with around a 30-40 amp fuse.

Bolting on a mechanical fan removes all the electronics, generally is more reliable, etc. Mechanical clutch fans can go bad, but it's not super common.

FYI, a vehicle can be ran with no fan at all, the trick is you cannot stop, red lights, drive throughs, traffic jams, etc with the engine running can make it overheat. Moving ~25mph+ it moves more air through the radiator than what the fan could ever pull, so you never need one to run 24/7.

As stated above, overheating can result in blown head gasket, wouldn't be a bad idea to check and make sure. If you're trying to get better mpg from the electric fan, it's such a tiny draw on the engine while driving it's next to nothing. Only at first startup, and idling stopped is there much of a measurable different on the engine. Mechanical is more efficient when it's needed, electrical has to be powered from the alternator, through wires, to the fan motor, there's atleast a 20% loss in all of that and the fan is only "one speed" while mechanical are kind of variable based on temp (how much it slips).