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Model specific boards => Golf mk2 => Topic started by: helliosjon on 15 June 2004, 14:17

Title: MKII fan Current
Post by: helliosjon on 15 June 2004, 14:17
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.
Title: Re:MKII fan Current
Post by: davidhawkins_78 on 15 June 2004, 14:23
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 ....
Title: Re:MKII fan Current
Post by: helliosjon on 15 June 2004, 14:29
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.
Title: Re:MKII fan Current
Post by: J a m e s on 15 June 2004, 14:32
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?
Title: Re:MKII fan Current
Post by: helliosjon on 15 June 2004, 14:41
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?
Title: Re:MKII fan Current
Post by: davidhawkins_78 on 15 June 2004, 14:59
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 ...
Title: Re:MKII fan Current
Post by: helliosjon on 15 June 2004, 15:46
Fair point, how do you check for or clear air locks?

Title: Re:MKII fan Current
Post by: J a m e s on 15 June 2004, 15:55
it will prob be a dirty sensor, mine is always going off when it gets hot >:(
Title: Re:MKII fan Current
Post by: davidhawkins_78 on 15 June 2004, 16:01
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 ..
Title: Re:MKII fan Current
Post by: helliosjon on 15 June 2004, 16:02
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?
Title: Re:MKII fan Current
Post by: helliosjon on 15 June 2004, 16:08
davidhawkins78
thanks for the advice, the blowers work ok so I'll try what youve said.

Awesome gti store sell thermostats and fan switches that trigger at lower temps than the standard ones. Does anyone have these fitted? do they make much difference?
Title: Re:MKII fan Current
Post by: benjam_in on 15 June 2004, 16:20
could be the first speed setting on ur fan isnt kicking in! and the fan is only starting up when the 2nd threshold is met!
Title: Re:MKII fan Current
Post by: benjam_in on 15 June 2004, 16:20
presuming its a 2 speed fan that is!
Title: Re:MKII fan Current
Post by: helliosjon on 15 June 2004, 16:24
how do you tell?
its a 1989 16v.
(if that makes a difference.)
Title: Re:MKII fan Current
Post by: J a m e s on 15 June 2004, 16:32
my light comes on just as the fan kicks in
Title: Re:MKII fan Current
Post by: benjam_in on 15 June 2004, 16:33
should be! check to see how many wire are attached to the back of it. if there are two then its a normal fan but if its got three its the fan with two speed settings!

if you wait till you fan kicks in then unplug it and test the connections for power!!! I think on full power they both should have power but im not sure so dont quote me!
Title: Re:MKII fan Current
Post by: helliosjon on 15 June 2004, 17:03
2 on the fan switch and 2 on the fan

I guess its the basic on then.

I might just stick a couple of tea bags in the expansion tank and have a brew up instead!
Title: Re:MKII fan Current
Post by: rubjonny on 15 June 2004, 17:14
Ok I would see about getting a different radiator temp sensor which makes the fan kick in at a lower speed.  One thing, does your temp sensor have 2 or 3 pins?
Title: Re:MKII fan Current
Post by: helliosjon on 15 June 2004, 17:22
its only got 2 leads on the fan switch.

if I got one with 3 connectors, what would i connect the 3rd  one to?
I only got 2 wires.
Title: Re:MKII fan Current
Post by: helliosjon on 15 June 2004, 17:25
sorry rubjonny,
I misunderstood what you were saying.
(reading things quickly while at wory you see)

You mean get a 2 connector one that switches at a lower temp?
Like the ones awesome gti sell?
Title: Re:MKII fan Current
Post by: rubjonny on 16 June 2004, 12:02
Yea thats right, looks like you need it to cut in at a lower temp.

Does the car overheat when driving though?  If so you have defo got something up with it as the airflow through the rad is more than enough when travelling more then 30 mph.  The fan should only be needed if the car isn't moving!

Does the lower radiator hose get hot when the temp is just over half way?  If not your thermostat is buggered.
Title: Re:MKII fan Current
Post by: rubjonny on 16 June 2004, 12:05
P.S. if you're feeling 'handy' it might be worth looking into getting your system upgraded to a 2 speed fan, I think you'll need a 3 pin tep sensor for the radiator and the wiring loom from the switch to the fan, and a 3 pin fan.

If you have a scrappers near you it should be easy.  Even my 1.6 driver has a 2 speed fan ;)
Title: Re:MKII fan Current
Post by: helliosjon on 16 June 2004, 13:13
the cars fine while driving, but as soon as I stop at traffic lights etc it goes right up.
Thats why I initially thought about putting an over ride switch on the fan so I could just give it a quick buzz while I'm stationary.
Title: Re:MKII fan Current
Post by: J a m e s on 16 June 2004, 14:26
im gonna do this on sat or sun, will take pics and do a "how to"
Title: Re:MKII fan Current
Post by: rubjonny on 16 June 2004, 14:57
Sounds good, I would get a sender that cuts in at a lower temp then, should solve your problem.
Title: Re:MKII fan Current
Post by: helliosjon on 16 June 2004, 15:27
I've ordered the fan switch and thermostat that cut in sooner so I'll try that, but let us know how you get on james.
Take lots of photos.
Title: Re:MKII fan Current
Post by: helliosjon on 23 June 2004, 10:36
Had the new thermostat and fan switch fitted yesterday also flushed out the Rad etc.
The fan now kicks in when the temp needle is just over the half way mark.
So no more kettle impressions for me.


Just as I sort out the cars cooling, the hot weather ends!!