Low Temp Fan switch

[Lousav]

Hello Fiat Friends,

My car runs hot and it's not a thermostat or air in the line issue. I recently took a 1,300 mile 4 day trip and when rolling i was at 195 but after a few minutes in traffic I bumped up to 230 pretty fast. The fan came on but it I was wondering if anyone had installed the low temp switch to get the fan running at 187-190? I was also advised that my radiator which I replaced about 15 years ago from international didn't have enough fins and I should consider an aluminum replacement. Any help would be appreciated.
Thanks,
Lou,
1980 FI Spider

[SteinOnkel]

First I would confirm the temperature gauge is reading correctly with an infrared thermometer. The gauges in the cars are woefully inaccurate. Mine read about 30* higher when I turn the lights on.

[TwinFast]

My car also runs hot several years with the same behavior and i solve the problem with a new thermostat (the old one was empty, with only the housing !) and i install a low temperature sensor ...

Since then, the needle of the temperature gauge never exceed the 0 of 190°F ...

[Lousav]

Thanks guys, much appreciated. Just spoke to Frank at Auto Ricambi and ordered the aluminum Radiator, low temp switch and just might install the after market fan I bought last year. I didn’t install the fan yet due to clearance but discovered if I mount it directly to the radiator I have the room I need.

Thanks again!

[TX82FIAT]

You have options but I'm not sure the options present a cure. You can install a fan switch that will trip the circuit at a lower temp. Many of the suppliers sell them. You can also install a manual override switch to manually turn the fan on. Some would argue a manual override switch is not needed in a properly functioning system and they are correct. However, in Texas when I know I'm at a long traffic light that may very well take several lights to get through the intersection, it is easier on the car to turn the fan on manually to start cooling immediately rather than waiting for the temp to trigger the switch. In my warped mind I see it as less temp variation and less metal expansion on a 40 year old vehicle.

I'm not sure either of these fixes will fix your issue. Rolling at 195 or a 230 temp when stopped is too hot. I'm with SteinOnkel on using a temp gun to test the true temp. You can get one cheap (a few dollars) at harbor freight. First thought is your not running that hot or you would have issues very quickly. If you are running that hot, then I would pressure test the entire coolant system if holding pressure and no leaks found, empty and flush the system. Before you flush the system, unhook bottom hose from radiator and take a standard garden hose and run it through the radiator. If the radiator is not clogged the water will flow freely out of the bottom. All this assumes your coolant and oil are clean, no air in system and tstat is working properly and you can feel all hoses are hot.

[Lousav]

Thanks so much,

Going to install the new aluminum radiator and switch in a couple of weeks. Will pick up the temp gun prior to installation to get a base line read. Not sure if the after market 12” fan will out preform the original fan that seems like a workhorse. All advice is much appreciated.
Thanks again!
Lou

1980 spider 2000 FI

[SteinOnkel]

A lot of a radiator's performance comes from the shroud. Most Aftermarket fans don't allow you to use the same shroud (or any at all) and are usually out-performed by the stock setup.

An extra switch is a hodgepodge "fix" at best. Your 39 year old classic deserves better.

80's VWs have two-stage automatic switches. They will supply 9V to the fan motor at one temperature and the full 12V at a higher one. Perhaps something like that can be retrofit to your car. Temp spec is listed as "95-84C/102-91C". Thread is m12, standard pitch I believe. I don't know what Fiat used. Anyways, here's the part number if you want to do some more digging: 191 959 481 C

[Lousav]

Actually the low temp switch I was referring to is supplied by AutoRicambi. It’s the same switch found in the bottom left hand side of the radiator and it kicks the fan in about 20 degrees sooner. Also installing the low temp thermostat. Time will tell, and thanks for the VW info.

[SteinOnkel]

Ahhh, okay! That makes more sense.

I thought you were referring to an additional on/off toggle switch in the cabin. I hate those sort of "fixes".