Author Topic: Radiator Fan Switch Test  (Read 7513 times)

July 05, 2011, 10:23:10 am

Smokey Eddy

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Radiator Fan Switch Test
« on: July 05, 2011, 10:23:10 am »
Does anyone know which colours (wires) i jump to make sure that if the thermo switch closes (on the bottom of the rad on an mk2 - tranny side) my fan will turn on (i have a different fan that i dont recall ever turning on...)
Im about to drive in the heat to some pretty hot places and cross the rocky mountains so this is fairly important to me that it works.
If it proves to be difficult i'll just relay the fan to a switch.
Thanks for your time,
Ed
Ed
Blacked out mk2 AAZ Jetta RIP. You are missed.
White 1999.5 ALH Golf 2dr. Low & wide. Rammed off the road RIP.
Blue 2009 CR140 Jetta CBEA/CJAA. Malone stage 2. EGR/DPF/Exhaust-valve deletes. 2.5" open exhaust. ADP Turbo swap. 1-stage nitrous kit. THROWN ROD

Reply #1July 05, 2011, 10:31:24 am

R.O.R-2.0

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Re: Radiator Fan Switch Test
« Reply #1 on: July 05, 2011, 10:31:24 am »
Does anyone know which colours (wires) i jump to make sure that if the thermo switch closes (on the bottom of the rad on an mk2 - tranny side) my fan will turn on (i have a different fan that i dont recall ever turning on...)
Im about to drive in the heat to some pretty hot places and cross the rocky mountains so this is fairly important to me that it works.
If it proves to be difficult i'll just relay the fan to a switch.
Thanks for your time,
Ed

red wire going into the connector is power from the battery. take and jump the red wire to either of the 2 other wires, and it will make one of the fan speeds operate. red and middle connector should be low speed, and red and the far wire should be high speed. i usually use a little chunk of stainless hard wire to make the test. dont jump the terminals for very long tho, the high speed circuit makes the jumper wire you use get hot in a hurry.
92 Jetta GLI - Black, 1.6D w/ GT2056V turbo..
86 GTI - 4 Door, Med Twilight Gray, Tow Machine..
86 Audi Coupe GT - Tornado Red, All Stock.. WRECKED.
89 Toyota 4Runner - Dark Grey Metallic, LIFTED!

Turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.

Reply #2July 05, 2011, 10:46:03 am

Smokey Eddy

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Re: Radiator Fan Switch Test
« Reply #2 on: July 05, 2011, 10:46:03 am »
How can I test the switch it's self? put it in boiling water, connected to power and wait for ... one of the wires to suddenly have continuity?
Ed
Blacked out mk2 AAZ Jetta RIP. You are missed.
White 1999.5 ALH Golf 2dr. Low & wide. Rammed off the road RIP.
Blue 2009 CR140 Jetta CBEA/CJAA. Malone stage 2. EGR/DPF/Exhaust-valve deletes. 2.5" open exhaust. ADP Turbo swap. 1-stage nitrous kit. THROWN ROD

Reply #3July 05, 2011, 11:08:50 am

vanagonturbo

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Re: Radiator Fan Switch Test
« Reply #3 on: July 05, 2011, 11:08:50 am »
no need to connect it to power. but yes, put it in boiling water with a thermometer. The temps that the switch should close at are written on the side of the switch. check continuity with an Ohm meter and verify that the switch closes at both temps.

Reply #4July 05, 2011, 11:14:27 am

R.O.R-2.0

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Re: Radiator Fan Switch Test
« Reply #4 on: July 05, 2011, 11:14:27 am »
no need to connect it to power. but yes, put it in boiling water with a thermometer. The temps that the switch should close at are written on the side of the switch. check continuity with an Ohm meter and verify that the switch closes at both temps.

couldnt have said it better myself!

the other way to test the switch, is let the car idle, if the temp gauge gets above 3/4 or so, the switch prolly dont work..

traffic jams are where i notice if my fan is or is not working.. and drive thrus at slow-food restaurants..
92 Jetta GLI - Black, 1.6D w/ GT2056V turbo..
86 GTI - 4 Door, Med Twilight Gray, Tow Machine..
86 Audi Coupe GT - Tornado Red, All Stock.. WRECKED.
89 Toyota 4Runner - Dark Grey Metallic, LIFTED!

Turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.

Reply #5July 05, 2011, 11:36:55 am

Smokey Eddy

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Re: Radiator Fan Switch Test
« Reply #5 on: July 05, 2011, 11:36:55 am »
Yes, i notice my temps rising pretty high in jams. That's what raised my concern initially. The needle would get pretty high say, the 2nd last white line on the mk2 gauge, and i could never hear the fan come on.
Thanks for the info guys!
What a quick thread this was.
Ed
Blacked out mk2 AAZ Jetta RIP. You are missed.
White 1999.5 ALH Golf 2dr. Low & wide. Rammed off the road RIP.
Blue 2009 CR140 Jetta CBEA/CJAA. Malone stage 2. EGR/DPF/Exhaust-valve deletes. 2.5" open exhaust. ADP Turbo swap. 1-stage nitrous kit. THROWN ROD

Reply #6July 05, 2011, 11:54:50 am

R.O.R-2.0

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Re: Radiator Fan Switch Test
« Reply #6 on: July 05, 2011, 11:54:50 am »
Yes, i notice my temps rising pretty high in jams. That's what raised my concern initially. The needle would get pretty high say, the 2nd last white line on the mk2 gauge, and i could never hear the fan come on.
Thanks for the info guys!
What a quick thread this was.

this thread probably would have made it 3 pages on the ol' whoretex..
92 Jetta GLI - Black, 1.6D w/ GT2056V turbo..
86 GTI - 4 Door, Med Twilight Gray, Tow Machine..
86 Audi Coupe GT - Tornado Red, All Stock.. WRECKED.
89 Toyota 4Runner - Dark Grey Metallic, LIFTED!

Turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.

Reply #7July 05, 2011, 12:16:24 pm

vanagonturbo

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Re: Radiator Fan Switch Test
« Reply #7 on: July 05, 2011, 12:16:24 pm »
Maybe its because we arent talking about strut bolts?  ???