The OVP may still warrant replacement, as the part is defective, even if the fuses are intact.
To determine if you have the OEM part, remove the OVP and look along the side for "Siemens Austria". If you see that, it is the OEM part and needs to be replaced. The OEM unit has been deemed defective due to poor solder joints. This was coded as part number 000-540-52-45 (which may also be embossed on the relay).
The corrected retrofit can be ordered and is now issued as part number 000-540-67-45. It's about $65 and FastLane has got 'em.
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car