The Auto Cool Guy needs information on fans for posting on this page.
The Mark VIII fan seems to be one of the best fans that can control your radiator temperature and powered with the Auto Cool III controller.
REPORTS OF FANS THAT HAVE A BUZZ PROBLEM:
4-5-2019: SPAL VA13-AP70/LL-63-63A
4-12-2019: DERALE 18212 12 INCH email@example.com
6-22-2019 Derale 16819 fan reported at buzz.
The BMW E60 M5 850 watt fan is a 3 phase
motor, 100 Hz 10-90 % duty cycle. The Auto Cool Guy has no controller for this type of fan! Great German design?
This is why switching a fan on from a dead stop will burn out your relay type controller. It looks like it peaks at 100 Amps! Soft start in the Auto Cool controller limits the in-rush DC current when started.