i've replaced three sensors for the cooling system and the fans still don't work. what next?

Question

how would i check to see if the wiring is bad or the fan motors

Answer 1

Check to see if that fan has power? And yes, a test light would be the way to do that. Then you'll need the schematic and trace down where the power is interrupted. If you have power you need a motor.

Answer 2

How are you testing the fans to see if they work ?? If you turn on your a/c the fan should come on, at least in most cars it does. I would guess the fan relay may have a problem not the sensors.
NEVER replace a part till you know the problem. Makes you sound like a "mechanic" when you say you replaced all those parts without a clue.

Answer 3

Make sure that you have a thermostat in the cylinder head.
If not put the correct thermostat in.
How do you know if the fan is coming on while driving?
Bridge the sensor with the motor "Stopped" and the ign switched on, the fan will operate if not there is problems with the electrical system.

Answer 4

Have to check to see where the current reaches. You'd need a multimeter on 20 v range or a test lamp and chech between the terminals going into the sensors and out to earth and see where you get power to. A circuit diagram would be handy too, to see where the current comes from. The problem may be further back in the circuit..

Answer 5

First of all what kind of car is it?Since you mentioned three cooling sensors it Sounds to me like a early 90's Honda? If it is I would check for power at the fan clutch, very common problem.

Good Luck

Answer 6

Disconnect the fan, and jump it to the battery with extra wires. If they run, then you know the fans good.

Answer 7

check fuses and relays first. if 2 fans, it may have 2 fuses and 2 realys

Answer 8

A test light. They're cheap. About six bucks.