1978 Fiat Spider

[Harrychin]

Hello just bought this car last week. The fan light on the right side in the cluster stays on when the key is off. The car had a patch job in the radiator so I put a new radiator in her today. I let the car idle it gets well in to 190 to 200 and fan does not kick on. The fan works as i jumped it with a 12 volt source.Top of the tank feels hot the bottom is cold. Could it be the fan switch on the bottom of the Radiator? Could the water pump be bad? Thermostat not working? Also way the light stays on lol ?
Thanks

[TwinFast]

It looks like the thermostat not working or the relay is out.

Best thing to do is to remove the thermoswitch and check if the fan come on when you "gently" heat it with a heat gun.

[PhillySpider]

Disconnect all connections on the fan and ground, clean and spray some contact cleaner. Fixed me right up...

[Harrychin]

I have done the clean all connections. Even took of the grounds wire brushed every connection. I will try the heat gun thing tho. Never thought of that. Thanks Does anyone know about what temp the fan should kick on?

[tima01864]

Do a search here aout filling the cooling system. There is a procedure with the engine to purge the air out, Sounds like you have air in the system.

[redcars]

+1 on air in the system. You said the bottom of the radiator is cold. That means the coolant is not circulating . This is most often caused by air in the system. The fan switch is in the bottom of the radiator so if the bottom is cold the fan will not come on. Until you get hot coolant in the bottom of the radiator all your work is wasted effort.

[Harrychin]

So took the radiator back out. Took a heat gun to the temp switch. The fan came on. While i had the radiator out I pulled off the water pump just to make sure the propellers were not rotted away. The car has been sitting for 7 years. It looked fine. I am thinking it is the air in the lines issue. Its that and or thermostat is not opening.The car runs get up and past 190 and the bottom tank of the radiator and top is still ice cold. I have worked on many older cars. i have a 68 nova and to check the thermostat in that car i would just pull it out of the manifold and put it in a pot on the stove and heat it up to see if it opened or what temp it opened at. My question is can you put that whole unit in a pot and boil it to see if it opens? Thanks

[TwinFast]

It looks like your radiator is too dirty.
The best solution is to flush your radiator with white vinegar. You will be surprised by how much dirt is inside

[Harrychin]

Is a brand new Radiator from Vicks.

[tima01864]

Did you bleed the coolant system?

[Harrychin]

After I put everything back together I will do that. I was just making sure everything was in working order. I ordered a new waterpump just because i figured why not. i will have it Saturday.

[Harrychin]

Well new problem and this was not happening before. Put radiator back in new water pump. Filled up radiator. Went to start the car and it revs up to like 4 thousand rpm. May go higher but I shut it off. Pulled air cleaner off nothing is binding. Still revs up with air cleaner off as well.

[Harrychin]

Figured out the high idle problem. There are 2 hoses that go into the back of carb. They run antifreeze threw them. I took one of the hoses off filled it with a turkey baster with 50/50 mix of antifreeze and water hooked it back up started can and idles fine now. I also took off heater hose filled that as well. Car get well past 190 fan still won't kick on. The temp switch at bottom does work as I heated it up with a heat gun and fan kicks on. The top of the radiator will start to boil. Gets real hot. The bottom tank of radiator stays real cold... Like there is no flow what so ever. I bought a 1.99 flush kit from NAPA that i am going to splice in to the heater hose to see if there is yet more air. I have looked at pictures on how the thermostat goes in and i see some have it one way and others have it a different way....As of now I have the fatter end with the ring going toward the Motor (Short Hose).