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General Information => Troubleshooting => Topic started by: mk2vr6 on September 10, 2007, 03:45:04 pm

Title: rad fan resistor (with A/C)
Post by: mk2vr6 on September 10, 2007, 03:45:04 pm

I went to the VW dealership and they wanted $78 for this resistor.

Is there another place I can get it for cheaper?  This price is a little over the top if you ask me, and bestpricecarparts.com doesnt have it.

thanks.

Title: rad fan resistor (with A/C)
Post by: Vincent Waldon on September 10, 2007, 03:53:49 pm

That *is* a bit nuts for a resistor.  By any wild chance are there any markings on the old one that indicate its value and wattage ??  

Anyone out there got one they could measure with an ohmmeter ??


Vince

Title: rad fan resistor (with A/C)
Post by: mk2vr6 on September 10, 2007, 05:15:07 pm

i read on here it was .82 or .86...  but high wattage.

Title: rad fan resistor (with A/C)
Post by: jimfoo on September 11, 2007, 10:02:04 am

JUNKYARD

Title: rad fan resistor (with A/C)
Post by: Vincent Waldon on September 11, 2007, 10:54:03 am

Yeah, depending on how I do the math it looks like it might be 200W... I checked some of my usual suppliers and it's not a common item (used to be, back in the day when people built their own audio stuff).  Could build it out of smaller resistors... if you can't find it in the junkyard lemme know and I'll do a bit more math.

Got a Radio Shack in your neck of the woods ?!

Title: rad fan resistor (with A/C)
Post by: mk2vr6 on September 11, 2007, 11:29:11 am

no no, over here its called "the source by circuit city".  haha.  same ***, different pile.

any help would be appreciated.

Title: rad fan resistor (with A/C)
Post by: jimfoo on September 11, 2007, 02:28:11 pm

http://dkc3.digikey.com/PDF/T073/1699-1701.pdf halfway down the page. Corrib Fixed Vitreous enamel power resistors - 280 Series
.63 or 1 ohm 300 watt $27 or $24. .63 will give it a little more speed, 1 will give it a little less.

Title: rad fan resistor (with A/C)
Post by: Vincent Waldon on September 11, 2007, 05:16:54 pm

Damn... I checked Digikeys site and everything... at least the Canadian one !!!

Good catch...

Title: rad fan resistor (with A/C)
Post by: mk2vr6 on September 11, 2007, 05:58:30 pm

I'm not ordering this yet, but I will be shortly in the future.  I think the link should maybe be made a sticky post or something in the FAQ section, because when you search the term 'resistor', you find a lot of people with a similar problem.  And seeing as the dealer doesnt stock the part anymore and the cost is around $78 for a single resistor, suddenly $25 doesnt seem so bad!

Title: rad fan resistor (with A/C)
Post by: clbanman on September 12, 2007, 06:58:20 am

While searching on this, I found a few people who said they had just bypassed it.  This would eliminate the fan's low speed, but would it actually cause any problems?  Your current draw would be the same.  If the fan was running on high speed, wouldn't it just run for a shorter period of time until the temperature sensor shut it off?  The only possible problem I can see is if the on/off cycle was extremely short so that the on/off switching caused fan motor durability issues.  Does anyone know if there is an actual downside to eliminating the resistor?

Title: rad fan resistor (with A/C)
Post by: jtanguay on September 12, 2007, 09:32:27 am

Quote from: "clbanman"

While searching on this, I found a few people who said they had just bypassed it.  This would eliminate the fan's low speed, but would it actually cause any problems?  Your current draw would be the same.  If the fan was running on high speed, wouldn't it just run for a shorter period of time until the temperature sensor shut it off?  The only possible problem I can see is if the on/off cycle was extremely short so that the on/off switching caused fan motor durability issues.  Does anyone know if there is an actual downside to eliminating the resistor?

the problem is that the fan runs 100% of the time with a/c enabled.  so without the slow speed, it will shorten the life of the fan motor, or the relays etc.  high speed does kick on when the a/c system reaches a certain temp tho, or the coolant.  the resistor on my car was blown when i got it.. so most likely it died on a really hot day, then everything cooked as the fan motor had to run on high mode all the time and wasnt designed for it.

Title: rad fan resistor (with A/C)
Post by: mk2vr6 on September 12, 2007, 09:46:47 am

Right now I have the resistor bypassed.  The only problem with this is that the fan doesnt kick on until halfway between 1/2 and 3/4 on the dashboard, where the 2nd speed would normally kick on.

If I could get it to kick on 100% but at the temp where the first fan speed kicks on, I would do that instead...

How hard is that?

Title: rad fan resistor (with A/C)
Post by: Doug on September 12, 2007, 05:15:02 pm

How about a standard 110v incandescent lamp in series where the resistor was? Just wire it up to a screw base for a buck and a half. It will surely be cheaper and although it won't glow at 12 volts you can experiment with different wattages to get different speeds. Makes a great conversation piece too!

Title: rad fan resistor (with A/C)
Post by: jtanguay on September 13, 2007, 06:52:45 am

Quote from: "mk2vr6"

Right now I have the resistor bypassed.  The only problem with this is that the fan doesnt kick on until halfway between 1/2 and 3/4 on the dashboard, where the 2nd speed would normally kick on.

If I could get it to kick on 100% but at the temp where the first fan speed kicks on, I would do that instead...

How hard is that?

you need to trace the wires going to and from the resistor.  its sort of a complicated system.