MKII fan Current

[helliosjon]

Anyone know how much current a MK II fan draws?
I want to run a live to it from a switch on the dashboard so I can turn it on and off when the temp starts getting too hot, but I dont know what rating switch / relay / wire etc to use.
Anyone ever done this?
Is it easy?
Is it a good idea?

Incase you're wondering why, its 'cos the fan doesnt come on automatically until the temp gauge is well over to the right and the car is turning into a kettle.

[davidhawkins_78]

Probably better to solve the problem than rewire the whole lot !

Have you tested the fan works? Have you checked the thermostat wiring etc ?

It's quite a simple citcuit /system, so should be cheap and easy to find the fault and have it working as VW intended ....

[helliosjon]

The fan does come in, but not until its really hot.
I've replaced the fan thermostat switch thing in the rad and checked all the connections but it made no difference.
Sitting at traffic lights the other day the needle went 3/4 over to the right and the red light started flashing.

i want the switch thing as a manual over-ride to give me peace of mind.

[J a m e s]

25-30amp

would be a safe measure, a friend i know used 18amp and it melted the switch.

i wanna do this, any tips of what wires to wire switch?

[helliosjon]

I was planning to fit a switch on the dash which turned on 40A relay which powered the positive side of the 2 wires on the back of the fan.

I'll put an inline fuse between the battery and the relay and use some decent size power cable.

Other than that, I'm still planning what to do.

Anyone got any ideas or suggestions?

[davidhawkins_78]

WAIT !!!

If the temperature light is flashing that's warning you about your coolant level's NOT your engine temperature !!!

I bet you've got a air lock and the system isn't cooling properly ...

[helliosjon]

Fair point, how do you check for or clear air locks?

[J a m e s]

it will prob be a dirty sensor, mine is always going off when it gets hot

[davidhawkins_78]

Check the forum for existing threads first - been talked about before ... there's a few valves that can cause air locks around the heater matrix - can u get hot air from the blowers ?

If that's a yes, then just set the heaters to full and hot, run the engine with the cap off for a bit so the thermostat opens, then top the expansion tank up. There's more involved to flush the system properly, but this should be ok as a quickie to sort the problem.

Also, remember  that the needle for temperature will sit pretty much at half for normal working conditions - so 2/3rds to 3/4 is about right for the fan to kick in ..

[helliosjon]

James,
How far to the right does your needle go before it flashes?

Anyone,

Is the Red light on the Temp gauge a low level warning light or a high temperature warning light or both?

Am I being a real dumb-ass here or can some one explain why a low level warning light would go off when water gets hot and expands?