Is my fan diagnosis correct???

[1idjack]

Fans were not working on my fiancee's 00 beetle. smaller fan motor comes on, but fan does not spin. the fan separated itself from the motor so it needs to be replaced. the larger fan won't do anything. it spins freely so i think it's ok, but when i jumped the pins on the thermo switch, the smaller fan motor would come on and the larger one would do nothing. sound like the fan control module?

[1idjack]

ok something else that i have a question about:

i have a round connector at the thermo switch. if i jumper from the 12v to pin 1, the small fan comes on. if i jumper from 12v to pin 2, nothing happens. this is with the key off. when i turn the key on and jumper from 12v to pin 2, the small fan comes on. is this the high speed setting where both fans are supposed to come on?

[btb]

Here's the guideline
1.Jump 1-2 : low speed both fans
2.turn on ignition
3. Jump 2-3 : high speed both fans
If one if the fan (or both) do/es not kick in, check the wiring and the fan(s). If they are good, then FCU can be faulty.
Both fans have to be on/off simultaneously. I think your radiator fan bites the dust.

[1idjack]

thanks. i used that same diagram you just posted to jump the pins on the connector. what i DIDN'T know was what you said about both rans running simultaneously. now i see what's going on here. oh, and by jumping these pins on the thermo-switch connector, i'm essentially by-passing the FCU, correct? how can i test the driver's side fan for operation? do i need to run 12v to that particular fan to see if it comes on? can you give me a play-by-play? if i can turn it on manually, that means the FCU is bad. if not, then the fan is bad and i'm buying one of these bad boys:

http://cgi.ebay.com/ebaymotors/98-03...spagenameZWDVW

MUCH cheaper than buying two separate fans from GAP.

just to get this straight one more time...

the jumper test will tell me one of two things:

1. jumping the pins successfully makes both fans come on. in other words, the FCU is toast.

2. jumping the pins does NOT make the fans come on. in other words, the fans or the wiring are shot

[btb]

Originally Posted by 1idjack

thanks. i used that same diagram you just posted to jump the pins on the connector. what i DIDN'T know was what you said about both rans running simultaneously. now i see what's going on here. oh, and by jumping these pins on the thermo-switch connector, i'm essentially by-passing the FCU, correct? how can i test the driver's side fan for operation? do i need to run 12v to that particular fan to see if it comes on? can you give me a play-by-play? if i can turn it on manually, that means the FCU is bad. if not, then the fan is bad and i'm buying one of these bad boys:

http://cgi.ebay.com/ebaymotors/98-03...spagenameZWDVW

MUCH cheaper than buying two separate fans from GAP.

just to get this straight one more time...

the jumper test will tell me one of two things:

1. jumping the pins successfully makes both fans come on. in other words, the FCU is toast.

2. jumping the pins does NOT make the fans come on. in other words, the fans or the wiring are shot

Here's the procedure:
1.Test if both fans are bad by running 12V and ground directly from the battery to each fan. The fan connector has 3 pins, one is ground (brown wire with black stripe)and the other 2 are hot wire (red with black stripe for High speed and red with white stripe for low speed). If each fan works for high/low speed go to 2. If not, replace it and see if the problem still persists.
2. Now you know that both fans are good, then the thermo switch connector is next, jump those pins using the diagram from the above post to make sure that wiring is good. If both fans work as it should, the replace the thermo switch. If not, the problem should be the FCU.
Note: by jumping the thermo switch connector, you're NOT bypassing the FCU. The FCU takes inputs from thermoswitch, battery, A/C pressure switch, etc.
DON'T buy cheap Fans. Go for an OEM

[1idjack]

thanks btb, i'll follow that and figure it out. what's wrong with aftermarket fans? had a bad experience? i've used aftermarket stuff before with great succcess.

[btb]

Originally Posted by 1idjack

thanks btb, i'll follow that and figure it out. what's wrong with aftermarket fans? had a bad experience? i've used aftermarket stuff before with great succcess.

They're flimsy but maybe bacause I'm a bit perfectionist. I've used only OEM parts in VWs and I think that's the way it should be.

[1idjack]

Originally Posted by btb

They're flimsy but maybe bacause I'm a bit perfectionist. I've used only OEM parts in VWs and I think that's the way it should be.

really? sorry for harping on the subject, but they look identical to OEM. even the blades are attached to the outer ring like OEM for stability. I was going to just swap the individual fans and use the OEM shroud since it looks like a pain to R&R. i guess you have first hand experience with the aftermarket fans?

[btb]

Originally Posted by 1idjack

really? sorry for harping on the subject, but they look identical to OEM. even the blades are attached to the outer ring like OEM for stability. I was going to just swap the individual fans and use the OEM shroud since it looks like a pain to R&R. i guess you have first hand experience with the aftermarket fans?

Not really. OEM parts are tested for fitment and longevity. Thier duty cycle usually much longer than cheap aftermarket parts. I bought a pair of foglights, advertised as an OEM. When I opened the box, it turned out to be aftermarket "DJ auto" which usually sold on ebay. The material and built are way off. But I can live with that as it's not a crucial mechanical part.But When it comes to the mechanical parts, use only OEM.

[razaksatar]

Hi,btb

My radiator fan's slow speed is open circuited for both fans. Since I know I will be replacing them, is it possible to interchange the cable between hi speed and low speed at the fan connector so as the hi speed fan will take the place of low speed cable. I presume under this condition the fan will always run at hi speed when the thermal fan switch is being activated at the lower temperature setting.

[MyOtherRidesAVette]

btb hasn't been on here since March (this is a five year old thread). I'm going to have to discect what you've written and see what it is you're wanting to do exactly. Are you not wanting to fix the problem? The correct diagnostics for the fans are late in this attachment.

Bentley Cooling System Diagnostics
Overheating problem

Sometimes, when I try to open up a link to something I have posted, it opens up corrupted. Somebody p/m me if this link doesn't work. Please. And send me the link to this thread, so I know which .pdf it is that's not opening. Thanks,

M.