OK, so I'm trying to fix this overheating issue I have on my town and country van. I may have to replace the cooling fan. Strange thing, the cooling fan has four wires conected to the motor instead of two. Does anyone know why there's more than two wires and what they all do?
TIA
Paul
The extra two wires are to prevent people like you from using a fan you bought 10 years ago for a different car and have sitting on a shelf. ;-)
Seriously, it's probably for a sensor that tells the car computer how fast the fan is turning.
Ted
Its a 2 speed radiator fan motor with a high and low speed relay
Hi Paul, I've been through this with my '94 Grand Caravan and know all about it. Max is right about the 2 speeds. The four wires are: low speed ground, high speed ground, Low speed 12 volts and high speed 12 volts. A single speed motor won't move enough air so forget that option. The way the 4 wire motor works is that there are 4 brushes on the commutator of the motor. When the cooling demand is low, the computer will enngage the low fan relay only. The low speed ground of the fan is permanetly connected to the negative, chassis ground of the van and the fan will then run at low speed. When you switch on the A/C or the engine needs more cooling the 2 High fan relays engage connecting the high speed ground wire to ground and the high speed 12 volt wire to 12 volts. At this point all 4 wires/brushes are in use and the fan runs at high speed. When the brushes of the motor wear down, which is common, the motor starts shorting out as the springs and brush wires fry the commutator. Low and or Hi fan fuses will blow in the fuse/relay center under the hood. I priced the fan at the dealer- 350 Bucks!! In my opinion, robbery!. Also you can't get just the motor from the dealer, just the whole assembly. I didn't bother with the junkyard route, as what they have will have some, if not alot, of wear on the brushes. I tried a single speed motor, which didn't move enough air even though the manufacturer claimed it moves enough air to sub for an engine mounted fan on a Chevy 350 V8. I ended up at autozone and spent $65 for an aftermarket 4 wire motor which is manufactured by Siemens for these vehicles. It is fantastic and appears to be better built than the original from Chrysler. That was 3 years ago with never a problem since. Hope it helps you out, Mike P.S. The motor will bolt right into your factory shroud and please note, the threads on the nut which attaches the fan blade are left hand.
Well done....are you looking for a job?
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