the cordoba resistor d. gale speaks of for replacement

[ryan-roopnarine]

of the bmw aux fan resistor is spec'd at 200 watts no matter who makes it, at least that's what i've found out today by checking x-ref books. the gp sorenson, wells, &c. &c...all seem to have ratings of 200 watts. if this is the case, it certainly makes it an attractive replacement for this part, especially since i haven't found one priced over $5.99 yet.

[gale]

The one thing I noticed with mine when I soldered a bunch of ceramic resistors together in series/parallel to get an equivalent .5 ohm/100 watt resistance, was the fan would still run at a high speed on the low circuit. Can't think why that would be a problem other than a little extra noise & wear & tear on the aux fan motor.

I eventually removed the resistor pack & put in the BMW Magna ballast resistor & low speed indeed went back to a noticeable much lower speed. Must be some dynamic effects at work here with the ballast resistor vs. the ceramics, due to heating, etc. Maybe a EE will chime in & give us a better explaination.

At any rate, $20 for a new BMW ballast resistor isn't going to break the bank & I added some heat-sinking to it along with lithium paste so maybe it will last a little longer. Still working fine 3 years later

[ryan roopnarine]

i was thinking that i'd have to do something about the wells part if i installed it. as a result of it being basically a big @ss ceramic resistor, its got an exposed element (like a heater element in appearance), i have to figure out something in the way of waterproofing and was thinking that i'd just strap a heatsink to the opening and put some rtv around it to seal it up. at any rate, its still $3.09 from autozone, available everywhere, and is only 1/6 the price of the replacement if it doesn't work out, and will help me figure out whether or not my system needs a top up of das r12.