Cooling Fan Replacement/Repair

[Fiatbrit]

Hello, I have a 1981 Spider and noticed the cooling fan never comes on. I also noticed that both wires going to the fan when plugged in are Hot. I assume this indicates a short in the motor allowing power to come thru to the ground side. When unplugged the wires coming to the fan are one side hot and one side not. Where could I find the best replacement and how hard it is to do? Please advise. Thanks again for all the help.

[RRoller123]

The fan is wired hot all the time, and the ground is switched to turn it on and off. The ground switch is located in the lower left (as looking forward) corner of the radiator.

Pete

[davery]

Hello, I have a 1981 Spider and noticed the cooling fan never comes on. I also noticed that both wires going to the fan when plugged in are Hot. I assume this indicates a short in the motor allowing power to come thru to the ground side. When unplugged the wires coming to the fan are one side hot and one side not. Where could I find the best replacement and how hard it is to do? Please advise. Thanks again for all the help.

I am going through the same thing right now. First, you need to figure out if it is the fan, radiator or the radiator fan switch. When the car is warmed up, is the bottom of the radiator hot? If not then the radiator is not circulating the water correctly and the switch is not reaching around 190 degrees to turn on the fan. If the lower radiator is hot you should check the fan switch. You should be able to turn on the fan by jumping the wires coming from the fan switch. I could not get the connector undone and had to cut mine to do so. If the fan comes on, I would think the issue is the fan switch.

[Fiatbrit]

thank you. Is it normal for both wires black and blue going to the fan to show as hot when connected to the fan? When I ground my test light to the pod and test both sides of the connector (while connected) both sides light the testlight. I would have thought that one side would be ground and one hot and therefore one side would not light my test light?? Please let me know your thoughts.

[focodave]

Fiatbrit,
Based on your voltage measurements and decription of the symptoms, it definitely sounds like either a bad fan switch at the bottom of the radiator -- or -- a bad connction or bad wire connected to that fan switch, not allowing the circuit to be completed when the fan switch makes contact internally (if the switch is good).
A simple test would be to bypass the fan switch (disconnect the wires from it) and jump the fan switch wire (the one coming from the fan motor) to ground.
If the fan comes on, you have a bad fan switch ---- assuming that the hot water is flowing properly through the radiator and that the hot water is reaching the fan switch at the bottom of the raditor.
Dave

[RRoller123]

It would be normal for both fan wires to be hot, since one side isalways hot and therefore when you probe the other, I think you are reading the low resistance through the motor windings (?)

Best thing as recommended earlier is to jumper across the fan swithch at the bottom left of the radiator and the fan should instantly come on. It is always hot, even with ignition off (or it should be anyway).

Pete

[Fiatbrit]

Thanks. I will try that and write back. This is a great site. Thanks for all the fast replies.

[Fiatbrit]

That worked. Fan came on. Must be a bad switch. I think OReillys and Advance Auto has them. Thanks for the help.

[RRoller123]

Auto Ricambi, Vicks, IAP all have those sensors.

[Fiatbrit]

Hello, Ran the car tonight and bypassed the switch. The fan ran fine but the car still was getting warm at idle. Does not seem to get hot when driving it. I noticed the lower hose was not very warm either. Does this indicate a plugged radiator? I also read somewhere that in order to top off these cars and remove air blocks you need to raise the front of the car to get the fluid to fill the air pockets. What is the best way to accomplish that? Should i drive it up on my car ramps and then fill the radiator? I will likely remove the radiator and have it cleaned and tested eventually but thought I would diagnose first. Please advise your thoughts. Thanks again for the info.

[RRoller123]

You don't have to raise the front of the car, but I usually do anyway. Just follow this procedure carefully, and make sure the bleed screw in the front coolant T is the highest point (unless you have a bleed connection installed on the heater hose).

[4uall]

+10 for above instructions

http://wwwe.fiatspider.com/f08/viewtopi ... verheating

[davery]

You don't have to raise the front of the car, but I usually do anyway. Just follow this procedure carefully, and make sure the bleed screw in the front coolant T is the highest point (unless you have a bleed connection installed on the heater hose).

Is this true on all Spiders? The reason I ask is that my radiator seems to have a radiator fill extension that seems to to be higher than the bleed screw.

[azruss]

the hoods on the 80s cars are more dolphin nosed and have room for a longer fill neck. Still the heater hose is the high point in the system. the trapped air still needs to travel uphill to get out. Even if the fill neck is higher, if any part of the system (ie upper radiator hose) slopes down, it can trap air. This is why massaging hoses and raising the nose helps.

[Fiatbrit]

Great advice everyone. Car now has heat and warms up slowly. Lower hose gets warm but still no fan without bypassing the switch. I will replace the switch along with clean and repair the radiator. Thnks again.