Technical Radiator fan not working

[slowmk2]

hello, this forum has helped me alot while working on my fiat and i need a little help on where to start first. After the new engine was fitted and running ive only realised now that i don't think the radiator fan has ever come on yet, i let my engine get up to temp [till the needle was just halfway] and still nothing, after that i disconnected the coolant temp sensor and the fan did not come on. I then inspected the wiring and seems to be okay, fuses look fine, but i wasn't sure which relay was for the fan, anyway i read you can connect a 12v power supply to test the fan, how do you do this?

also I'd like to add that my lower radiator hose would not get hot, the top one will but not the bottom. The top hose also feels quite squishy but im not sure what im looking at and if that's an issue

thankyou!

Kins

 

[slowmk2]

update: managed to wire up the fan to battery, and it works fine, swapped the relays and tried unplugging coolant sensor with engine running and still nothing

 

[judderbar]

update: managed to wire up the fan to battery, and it works fine, swapped the relays and tried unplugging coolant sensor with engine running and still nothing

the fan relay is the large one so you cannot swap it with the other relays. If you remove the relay and connect the two large connectors in the fusebox the fan should work

 

[slowmk2]

the fan relay is the large one so you cannot swap it with the other relays. If you remove the relay and connect the two large connectors in the fusebox the fan should work

so am i missing a fuse?

 

[judderbar]

Sorry my mistake, I suppose only the cars with air conditioning have the large relay

https://www.elektroda.com/rtvforum/topic3337657.html

 

[slowmk2]

Ok. I led you astray a bit. But i think your car should have a relay in position 6 for the radiator fan. I suppose only the cars with air conditioning have the large relay in position

That's what I am thinking, i don't really understand this much but from what i can see here is the engine cooling fan even without air con has a relay at the bottom of fuse box [R6]?

 

[varesecrazy]

One of the controls is next to the fan..

Have you checked that ?

 

[slowmk2]

That's what I am thinking, i don't really understand this much but from what i can see here is the engine cooling fan even without air con has a relay at the bottom of fuse box [R6]?

ignore that, someone marked the fuses wrong, R6 is the red relay at the top left im pretty sure

 

[slowmk2]

One of the controls is next to the fan..

Have you checked that ?

fan switch ?

 

[Brendan W]

The ECU earths the fan relay via a little grey wire that runs from below the fusebox to the ecu plugs. If it gets broken as mine did you will have the symptoms you have. A test is to lift the fan relay a little, get a wire in at the earth pin, ground it somewhere handy with the temp sensor disconnected and now does the fan run.
The pin is 85 if I'm not mistaken and it runs to B8 on the ECU, our 2001 Mk2. Another way is just test that wire for continuity. The break was at a bend in the harness about midway between the fusebox and the ECU.
When you disconnect the temperature sender you should get a red flag on the dash and a slight increase in idle speed. Then you know the car is reacting to the 'missing' sensor and it's just lost sight of the fan relay.

 

[Mike1alike]

And for the lower radiator hose not getting hot (and most probably no heat inside the car), here is a real fix that I've done and the heat is still working great in my car:

I fixed the car heater (little radiator inside the car) | FIAT Punto (Mk2/2b)

Hello everyone, I will share with you this great fix, for the case your heater is not working but cooling system works fine, engine temperature is steady good and thermostat works fine. So everything works just fine, then winter comes alog and you have no heat inside the car. And also, it's...

www.fiatforum.com