Radiator fan not coming on

[trism]

My commodore, the only time the fan comes on is sitting in traffic on a hot day.

But if you're worried about it, replcae the thermostat.

Sent from my custard cannon like Peter North.

[Bludger]

Shorted the plug and the radiator fan came on fine.

It's hard not to worry about it, that's all. All other cars I have owned have to turn on their radiator fans to maintain engine temp. It doesn't make sense this car doesn't need to, maybe it has some sort of super dooper coolant? Last thing I want is my car to blow up in a traffic jam...I might get someone to have a quick look.

I've found there are 3 parts that control the fan coming on, and the reading on the temp guage:

- engine coolant temp switch (on the thermo housing, tells fan to come on)
- engine coolant temp sensor (under distributor, measures temp coolant?)
- engine coolant temp guage sending unit (under distributor, relays message to temp guage)

Wonder if I should just replace them all...

chage the fan switch where that plug was plugged into.

guarantee problem solved. you know the fan works.

[rhys.l]

Yeah you guys were right, thankyou!

After it was warmed up, I idled the car at 3000rpm for a good 5 minutes. And sure enough, for a brief 3 seconds or so, the radiator fan came on. There obviously needs to be some pretty extreme conditions before it is triggered. Very happy anyway

[Vtakk]

Probably leave it alone, it works!

Same thing happpened with my car man.. I was 100% it didnt work.. since it never came on after long drives, hot days etc.

It would only come on when needed.. and apparently my car never needs it xD

But I did manage to make it come on.

Your choice man.

I remembered my old Honda accord's fan wont turn on unless it needs to. If the fans left on..it will make alot of noise when idle and driving. As long the fans work and spins when need to its fine... if it doesnt turn on at all then yeh there mite be a problem lol
as long you got a super duper awesome radiator coolant and its still fresh and green then your the awesome

[Bludger]

Yeah you guys were right, thankyou!

After it was warmed up, I idled the car at 3000rpm for a good 5 minutes. And sure enough, for a brief 3 seconds or so, the radiator fan came on. There obviously needs to be some pretty extreme conditions before it is triggered. Very happy anyway

3 seconds sound a bit short.

I know that DC2 with after-market full size aluminium radiator, it NEVER gets to operating temperature.
Have to sit there revving for nearly 10 minutes before fan comes on.

Just be aware that your fan came on when you shorted the wires, but make sure your fan switch is operating correctly. like I said, 3 seconds is short.

Cooled coolant should take nearly 10 seconds more or less(most likely more) to circulate from the radiator, throughout the motor then to the thermostat housing where the fan switch is.

[rhys.l]

Yeah when you put it that way it seems as if there could still be a problem.

Just before the fan came on, we put aimed a heat gun at the upper radiator hose and it read 82C. According to the guy next to me, that was barely hot enough even though at that instant the fan did decide to come on. I think at this stage I'll just trust my engine temp guage and just keep an eye out for any signs of overheating.

BTW I was given and am running blue OEM coolant. Vtakk mentioned green above...is blue the right stuff for my car?

[Vtakk]

hmmm im not sure. But i know that most radiator coolants are green or greenish colour

[rhys.l]

Apparently I have the right stuff, OEM is just blue