Electric Fan Switch

[NickFerrell]

Hey guys
I was having trouble with my fan (as in, my fan wasn't working), so I jumped the two wires on the back of the switch, and it came on. Naturally, I replaced the switch. The fan still doesn't seem to be kicking on until the engine reaches 225/240. That's too hot! The lower radiator hose is hot, as is the bottom of the radiator. I'm at a loss.

[divace73]

Hey guys
I was having trouble with my fan (as in, my fan wasn't working), so I jumped the two wires on the back of the switch, and it came on. Naturally, I replaced the switch. The fan still doesn't seem to be kicking on until the engine reaches 225/240. That's too hot! The lower radiator hose is hot, as is the bottom of the radiator. I'm at a loss.

could the new switch be faulty?? Se if you can use a thermo gun to measure the temp around that area.

[aj81spider]

The other possibility is that your gauge/sensor is faulty.

[bradartigue]

With the car warmed up unplug the overheat switch wire from the head. See if the gauge moves into the normal range.

[NickFerrell]

With the car warmed up unplug the overheat switch wire from the head. See if the gauge moves into the normal range.

Overheat switch? That's not the same as the tempurature sender by the spark plugs, is it? Where is it?

[bradartigue]

there are two wires in the head - one is the needle, the other is the overheat. You can determine which is which by unplugging one of them; if it falls to zero then it is the needle. Plug it back in. The overheat should have absolutely no effect on the needle when unplugged (the needle should stay where it is). If it does not then the overheat switch is bad. The overheat switch is designed to send a signal ONLY when the car is overheating - the signal sets the needle to 260 (all the way right). When defective it adds 10-20 degrees to the needle, and gives you a false high reading.

[4uall]

This might help

http://www.international-auto.com/fiat- ... cation.cfm