Hey guys, new to this forum..

Problem with my fiat punto 2004, my radiator fan will not ever turn on, causing the car to overheat slightly in traffic.

I have tested the fan motor by running power to it individually and it works fine.

I have tried shorting the temp sensor and that did not cause the fan to work either.

Any ideas to where the problem may lie?

Cheers

Check relay and fuse in under bonnet fuse box.
Don't short the wiring to the sensor.!!
You could bridge the relay by using a fused piece of wire, link pin 30 (live) to pin 87(consumer/fan)
PIN numbers are on relay.

mistral said:

Hey guys, new to this forum..

Problem with my fiat punto 2004, my radiator fan will not ever turn on, causing the car to overheat slightly in traffic.

I have tested the fan motor by running power to it individually and it works fine.

I have tried shorting the temp sensor and that did not cause the fan to work either.

Any ideas to where the problem may lie?

Cheers

Click to expand...

hi,
use SEARCH to find all the other threads about this..,
https://www.fiatforum.com/punto-ii/435674-fan-test-2.html

you can use a software program to call for the fan..,
at least it's easier to see what's required then.

Have you tried disconnecting the temp sensor with the ignition on or car running ?
That should put the fan on within a few seconds.
The relay has four wires. Two permanently live supply the fan contact pole and the relay coil. The other two are the fan supply and the trigger earth wire to the ecu. The ecu triggers the relay by earthing a pale grey ( usually) wire. If this wire has been damaged the ecu will not be able to trigger the fan relay.
In my case the wire had been pinched where the harness goes behind the battery box.
I found it by paring back insulation on the wire at the ecu plug and failing to earth the relay with a short jumper wire from that point.

Yea that was me on the thread, unplugging the temp sensor put the fan on but still wouldn't work till i changed the sensor, if fan comes on when unplugging the wiring is ok apparently.

jazz452 said:

Yea that was me on the thread, unplugging the temp sensor put the fan on but still wouldn't work till i changed the sensor, if fan comes on when unplugging the wiring is ok apparently.

Click to expand...

Yes
The low current side the ecu controls of the relay
The ecu see open circuit on the fan vs 5v in, the ecu shorts to ground opening the low side of the relay
This activates the high side = pretty much whole circuit tested bar the sensor

Ziggy

Same thing happened to me mate check the grey wire that
Runs from engine fuse box over the battery mine was split
So cut it and put it back together worked perfect

If you have or know anyone with ECUscan it has an option to test the fan