Aloha,

1st, thanks for any help, as this one has me stumped. I have a 1998 Honda Crv and the radiator fan doesn’t come on unless you turn on the AC, where then both the radiator and AC fan come on together.

i found a bad relay, when I switched my radiator fan relay and AC fan relay. So I swapped it for a new one and still it wouldn’t come on.

and yes, I would wait about 5 mins for the car to heat up to check if the radiator fan would come on, but it wouldn’t.

I assumed the engine coolant temp sensor went bad so I installed a new one, but still doesn’t run the radiator fan without the AC on.

I am thinking the fan switch could be bad, but I am a bit lost now.

got any ideas? Please help

 

With a scan tool.Check the ECT and see if it's just not getting hot enough.