[Qmulus]

For what it is worth, my '03 S has/had the same 986 641 213 02FHB as yours. The 03 FHB should be fine. With the '03s and '04s with the MOST bus radios, earlier cluster firmware versions won't work right as they don't have the provision for the radio communication. From experience, I know the radio will work with a different cluster until you disconnect the battery or radio. Then it will go into protection mode and be locked out.

I have repaired quite a few of the late 986/996 clusters. While they look similar to the early clusters, the hardware and firmware are totally different. There are actually two EEPROMs in these clusters, and you cannot read them directly as the data on them is encrypted and is keyed to the processor. These can only be read and written through the K line.

As for replacement, if it cannot be repaired (I haven't seen one yet that couldn't be), it would be easiest if it were "cloned". Whoever does that will need both of the clusters at the same time.