Radiator fan did not kick in

WAN_DOOHAN

MEMBER
2008 HONDA STREAM
1.8L
4 CYL
2WD
AUTOMATIC
85,000 MILES

Hi. Found out yesterday that the radiator fan did not kick in even when coolant temperature hits 109 degrees Celsius. This is when the A/C switched off. With the A/C on, the fan will run.

Secondly, the coolant temperature starts to run at 100 degrees Celsius recently. Before this, it runs at 90 degrees Celsius. This is with the A/C on. Thermostat and radiator cap changed new.

Coolant temperature monitored using ScanGauge2.

Please help. Thanks.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
47,702 POSTS

Hello,

It sounds like the PCM is having an issue. But to be sure let's check for signal from the PCM to the control relay. Here is a guide and the cooling fan wiring diagrams so you can see how it works:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

It looks like there are two fan can you confirm?

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.

Images (Click to make bigger)