Hi all, thanks for this great forum. It has been incredibly useful, and I have now done several jobs on my '05 MCS (replace upper engine mount, replace alternator, replace idler pulley) that I didn't think I would ever be able to tackle!

Next on the list is the famous low-speed fan resistor, which of course is blown on my car. My fan assembly has a 1-plug harness, so there's only the resistor in the fan assembly, and the low-speed relay is in the fuse box.

I know there are a few widely discussed and used options out there: (0) ignore this and let the engine run hot (or turn on the A/C); (1) replace the whole fan assembly; (2) replace the resistor in place; (3) bypass the resistor to run the fan high-speed also in low-speed mode; (4) install remote power resistor mounted on the chassis or other heatsink. And I know that all have their pros and cons and their fan base (no pun intended).

As I would like to keep the car close to stock, I am considering option (2) with the Dorman 902-706 resistor, which is sold through some vendors. The resistor on this unit is quite different from the OEM resistor: From the pictures, it appears to be a round wire as opposed to a ribbon, it's not on a cylindrical support, and there's no green coating. Some 1-star purchase reviews mention that the spot welds are pretty bad, but that they can be patched up with some solder.

Does anybody have experience with this resistor? What is its resistance? Does it work as a replacement? How long does it last? Is it better than OEM, or worse? If it fails, how does it fail?

Side question: what's the little device wired in parallel to the resistor, and what is its function?

 

URO one is on backorder: https://www.northamericanmotoring.co...esistor-2.html

We have the dorman version as a backup, little different design otherwise you have to replace the whole fan unit and shroud which comes with a new one in oem design. Most said its ok and just watch for the welds. We carry lifetime replacements on most parts we sell.

https://www.ecstuning.com/b-dorman-p...t/902-706~dor/

All of the info that we know of its talked about in that main thread. People made their own versions also https://www.northamericanmotoring.co...ispreloading=1

 

I've used the Dorman to replace two failed OEM resistors. Dorman appears to be more durable (although my installations are only a year old) as the wound wire is more robust than the OEM resistive 'tape' on the factory setup. I did a bunch of research before installing and this seems to be widely preferred to the OEM part.

 

For the next person who is going to look for this: I bought the Dorman resistor kit. It looks like the spot-welded connections are covered under something that looks like (dried) liquid electrical tape. The little component next to the wire resistor is a thermal fuse RY184 for 184 °C, rated at 250V and 15A. It's wired in series with the resistor. The resistor itself is about 0.5 Ohm.