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montanasynchro
Samba Member
Joined: April 10, 2012
Posts: 8
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 Posted: Fri Feb 13, 2015 6:21 pm Post subject: Radiator fan resistor-2 wired on a 450 W motor |
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Hello,
I have 87 Synchro Weekender with a 450 W fan motor. No a/c. My low speed fan does not work.
My old resistor is a two bodied style with only 2 wires at plug. One wire each on a total of two resistors. It looks like all that is available is 3 wired resistors and mine is a odd duck. I have pretty much given up trying to find what I need. I can not find previous posts about my type of resistor style and Bentleys does not help.
The folks at the various Vanagon parts places can not help me, so perhaps someone out there can.
Just curious if any one else has had this issue. Any help would be appreciated.
Thank you |
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crazyvwvanman
Samba Member
Joined: January 28, 2008
Posts: 9919
Location: Orbiting San Diego
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T3 Pilot
Samba Member
Joined: January 10, 2011
Posts: 1507
Location: Deep South of the Great White North
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montanasynchro
Samba Member
Joined: April 10, 2012
Posts: 8
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| Posted: Sat Feb 14, 2015 9:13 am Post subject: |
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All,
Thanks for your help and the correct part number. I talked to ECS and the resistor is available .
I believe the resistor is bad as I jumped the wires at the thermo switch and only had the high speed. I only have the one 30amp fuse and wiring which seems good. As far as troubleshooting, I have seen some posts about 19.2 in Bentleys having diagnostics for the fan etc. My copy of Bentleys on that page has very little info, just the temps which the thermo switch work at. Not that I like to renew parts that I am not 100 % sure are defect, but the new resistor is pretty cheap and my old 27 year old resistor must be feelings its age.
I was using the write up at GoWesty about trying to understand my system better and was under the impression that only 450W fans had resistors and from the description they give, my fans seems like its the 450W.
I am wondering now if the lower power fans in later Vanagons had resistors.
If anyone can shed some light on that, I would appreciate it.
Anyway, thanks to both of you and have a good weekend.
Tom |
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crazyvwvanman
Samba Member
Joined: January 28, 2008
Posts: 9919
Location: Orbiting San Diego
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| Posted: Sat Feb 14, 2015 9:41 am Post subject: |
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Along with all the good info in the GW tech articles there are various errors of omission and just plain errors. Too bad they don't fix them. The 450 watt fan was used on Syncros whether they had factory A/C or not. The wiring is different for Syncro non-A/C with a 2 speed fan instead of a 3 speed and the diagram that shows your setup is on page 97.200 of the later Bentley.
The small 200/300 watt fan motor has 3 wires built in to let it have 2 speeds internally. The larger 450 watt fan motor has only 2 wiring connections and then external resistors are used to slow it down. The 2 wire resistor like yours make 1 low speed. The more common 3 wire resistor creates 2 lower speeds, a low and a medium. The fan wiring harness matches either a 2 wire or a 3 wire as fitted from the factory.
Mark
| thmacki wrote: |
All,
Thanks for your help and the correct part number. I talked to ECS and the resistor is available .
I believe the resistor is bad as I jumped the wires at the thermo switch and only had the high speed. I only have the one 30amp fuse and wiring which seems good. As far as troubleshooting, I have seen some posts about 19.2 in Bentleys having diagnostics for the fan etc. My copy of Bentleys on that page has very little info, just the temps which the thermo switch work at. Not that I like to renew parts that I am not 100 % sure are defect, but the new resistor is pretty cheap and my old 27 year old resistor must be feelings its age.
I was using the write up at GoWesty about trying to understand my system better and was under the impression that only 450W fans had resistors and from the description they give, my fans seems like its the 450W.
I am wondering now if the lower power fans in later Vanagons had resistors.
If anyone can shed some light on that, I would appreciate it.
Anyway, thanks to both of you and have a good weekend.
Tom |
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montanasynchro
Samba Member
Joined: April 10, 2012
Posts: 8
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| Posted: Sat Feb 14, 2015 11:12 am Post subject: |
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Hi Mark,
Things are finally clear for me. Its the first time I had to post on the Samba as I can normally figure things out from old posts etc.
Its nice to know that help is out there when you are stumped.
Thank you,
Tom |
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eaders
Samba Member
Joined: September 06, 2016
Posts: 11
Location: Canada
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| Posted: Thu May 13, 2021 6:52 am Post subject: Re: Radiator fan resistor-2 wired on a 450 W motor |
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Old thread, I know.
Does anyone know how to use a three-wire resistor for the 450w setup?
I ordered the three wire one not realizing there was a difference. I’m trying to upgrade my ‘82 to the 450W setup. I’m using the wiring diagram from pg 97.200. I’m thinking there must be a way to use the three-wire resistor in a two stage setup...
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MarkWard
Samba Member
Joined: February 09, 2005
Posts: 17110
Location: Retired South Florida
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| Posted: Thu May 13, 2021 7:25 am Post subject: Re: Radiator fan resistor-2 wired on a 450 W motor |
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I can't be sure, but the further down the resistor you go, the more resistance = slower spinning fan. So, I'd use the terminals on each end as a trial, if you are not happy with the slow speed, move up one connector from one end and retest. Sorry that is not more helpful.
I added a 3 speed fan setup to our 82, and recall, since I was using a resistor from a Eurovan, I had to figure it out. The ohm meter barely shows any difference end to end. Its the load resistance that slows the fan down.
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