Radiator Fans for the Boxster and 911

Nearly all modern water cooled Porsches use the same radiator fan setup and should share similar parts. The basic troubleshooting should work on pretty much every car, but some part numbers might vary. They should be pretty similar for most 986 and 996 Porsches, however.

Part Numbers and Links

  • Radiator Fan part # 99662413500
  • Resistor part # 99661610100 (This is included in the fan and is very expensive when purchased separately) 
  • Relay part # 141951253B (This relay is used for many systems and may not be listed as a fan relay. At least on my Boxster, it is still correct for this application.)
  • Coolant temperature sensor part # 99660641000

Fender Liner Clips and Screws

These parts are reusable, but I find the clips often break or are missing. It's a good idea to have a few spares on hand. 


  1. You mentioned that the radiator fans are on high with the A/C on. How do you check the low speed?

    1. They're actually on low when the A/C is on. To test the high speed, you can jump the relays (as I discuss) or use a Durametric tool (not discussed because I only recently acquired the Durametric cable).

  2. I enjoyed your video - thank you for the information!
    I noticed that when you removed the inner fender shroud, the triangular plastic cover was missing, and I have the same problem. I have learned that this causes the ballast resistors to fail if cold water hits them. Did you replace them? If so, what is the part number for each side?
    Thanks again for your good work!


Post a Comment