Engine running hot.

[cougarman]

I have a 1981 Fiat Spider and a while back I was driving it home and it started overheating. So I pulled over and came back to it later and finished driving it home. It did get hot the second time. So I sat it in my driveway until I could get a chance to look at it. I saw that the water pump was missing its pulley. I found the pulley and it looked as if the person I had change the water pump only used one bolt to attach the pulley and it sheared off. I replaced the pulley and ran the car. It got to a little past the 190 degree mark and he fans never came on. The car has been sitting for a while. I am trying to sell the car because I need the money and need to figure out how to fix this fast. Any ideas on how to check to see if the fan is still good? However, I do not have a wiring diagram for the car. Any help would be greatly appreciated.

[124JOE]

on the RAD "on mine"theres a temp switch unplug and jump the wires from the harness
and the fan will run so keep clear
if the pully is tight now your fine

[rlux4]

The two components that operate the fan are the fan motor, and the temp switch Joe mentioned. The temp switch for the fan is the one at the bottom of the radiator, driver's side. You also need to make sure the ground is good. The ground is the largest black wire on the grounding pod that's on the inner fender towards the front on the driver's side.
Unplug the connector coming off the fan and run a hot wire and a ground to it, if the fan is good it'll come on. If it's good and you've checked that you have a good ground then you have to look at your temp switch. With the car hot at or above 190° you should have continuity across the terminals of the switch, you can check this by disconnecting the connector coming off of it. Sometimes this connector will go bad, while it's disconnected check for corrosion on the terminals.
Ron

[fiat218]

my fan did not work either till i polish up the ground pod. now it back to working at a tad over 190 degree

[cougarman]

Thanks for the responses. I will check these things out tomorrow.

[TX82FIAT]

If your horn works it is most likely not a ground issue.

[rlux4]

TX82FIAT, the horn and temp switch don't share a common ground terminal. They both may share the same pod, but it's a separate terminal. On mine the female spade was so loose it caused my fan not to come on. I tried squeezing it to get a better connection but the terminal was so bad it wouldn't work, so I put a new one on and solved the problem. The horn worked fine.
Ron

[JConnerly]

Don't forget the basics. Make sure there is no air in the cooling system. After trying everything else this solved my own overheating problem.

[TX82FIAT]

Ron, I think you are right about the circuit for the fan motor. I had a glitch with my fan and when the fuse blew my horn would stop working. As a result, I assumed the fan and horn were on the same circuit. My mistake. Just one of those funny things that i would check the horn when out for a drive to make sure the car would not overheat.

[cougarman]

I checked it out the horn works so its not the fuse. The lower radiator hose gets hot so the thermostat is opening. The only thing is the ground or the fan motor. However it is impossible to trace the ground/power wire. I really need to remove the dealer installed air conditioning.

[cougarman]

Ok here is some new information. The fan has 2 wires coming off of it. A blue/teal color and a black. I assume black is the ground. I unplug it plug only the blue side in. And run another wire to the black side to another ground on the car. And the fan will run. So the fan works. Does the fan switch have a positive and negative running off of it? Or should I just ground it out from the fan.

[dmwhiteoak]

The fan switch( on bottom of rad) only completes the circuit when temp is reached. A hot wire should plug in on one terminal and when temp is reached the other terminal is energized sending power to the fan. If the Connections are good, a good ground on black wire, mine goes to fire wall, fan should run. Check all your connections. If it still does not work check continuity between terminals on rad when-above 195 or a little more. One time mine did not come on till 200. I chNged switch and works fine.

[rlux4]

You shouldn't need to trace the whole length of the ground wire, just look at the ground pod near the front of the driver's side inner fender. The largest black wire on the pod is the ground for your fan. See if it's loose. or corroded.
Ron

[kiznarsh]

I just ran into a similar problem with my radiator fan not working. With the engine above 190, I checked continuity on the connector directly coming off the radiator switch, and it was solid. After cooling down, I checked the voltage across the 2nd connector (the one that hooks up to the connector coming off the fan) and it was fluctuating below 0.5V, and then it suddenly jumped to ~13.5 Volts when it got hot enough, so the switch is definitely working.

I tried what cougarman did and just hooked up the positive terminal on the fan switch and ran a separate wire from the negative to the ground pod on the inner fender wall. I tried all the terminals to get something going, but no dice (unlike cougarman who got it to run this way).

At this point, is there any doubt that it's the fan motor itself that I need to replace?

Thanks.

[narfire]

I checked mine by driect conection to a 12V battery and ground. Fan worked. Fan did'nt come on when temp said 190 because I had air in the system after pushing the heat lever in the car and opening up the heater core. Spent 5 minutes burping it again until I saw coolant flowing in the top of the rad. If there is air in the system the rad temp sensor will not get above 190 to signal the fan to come on.
Chris