Outer Limits 4x4 Board

Guys just wondering how you can test to see if thermo fans are actually working.
This is for me daily driver pulsar i know it not 4wd but thats in the shed>
Is there a way to put resistance or ohms on the sensor to make them work or do i have to go to the Dealers and get reamed.
1 pulsar me oldladys the fans turn on on a cold day mine dont it aint hot yet they turn on with aircon on .
Any help appreciated.
Dave

What model Pulsar is it?

Usually there are two fans- one will switch on with the A/C and the other will switch on when the engine is hot. Depending on your car model the thermo could controlled by a thermo switch mounted in the water jacket somewhere- or controlled by the EFI computer (N13 and later Pulsars fall into this category.)

Thanks for the reply its a 99 model.
doesnt seem to be getin hot just wondered why the other 1 turns on and this 1 doesnt maybe this 1 is running cooler?

One will be set turn on whenever the aircon is turned on. Turn it off and they will both opeate on temperature alone. The Nissan ECU may have control over the fan operation to the extent that it can stage and stagger their operation. For example the twin fans on EF Falcons were a dual speed setup. I run twin EL fans on my V8 and run both off a thermo switch, with an input from the air con compressor to turn on one of the fans whenever the air is turned on.

I don't know pulsars well enough to say either way. For that matter, I didn't even know they ran two fans. Pulsar owners?

fit a dash light and you can keep track!

or pull the plugs put 12 volts direct see if the fans are working. if its a thermo switch use a multimeter to check for continunity when hot and cold and make sure its different.

just let it idle in the driveway on a hot day, no airflow over the rad will soon heat things up, then they should come on, keep an eye on the temp gauge if you're worried, would be easiest to do this after you get home and the cars warmed up, then you won't have to wait so long.

Take it out, warm it up and then give it a good thrashing (the car that is!) and then immediately pull over and let it idle. That will get the fan to come on very quickly.

Given that the N13 Pulsar had the ECU controlled fans I'd be betting your later model does too. Check and you should find a fuse and a relay somewhere for it. Check they are both OK and (if you're game) work out which pins of the relay short to activate the fan and short them- that should kick it into life. Fault find it from there.

BTW most FWD vehicles have two thermo fans - one is controlled by the aircon (for the condensor) and the other is controlled by engine temp. Generally only older cars have thermo switches (~up to early '90's) these days the ECU does it all.