Date registered: Dec 2010
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New secondary air pump burned up
Recently replaced the secondary air pump on 1999 ML320. The old one was burned up so thought this will be an easy repair. Installed the new pump, cleared the fault code, closed the hood. Four days later the check engine light came back on. Checked the codes and sure enough "secondary air fault". Checked the fuse and yep its blown. Test the air pump motor and it was burned up. Soooo, what would cause the two pumps to burn? If the valves were not opening or the ports in the head were clogged it would seem that the fan would dead head but as it is only supposed to operate on cold start it does not seem that should overheat it to failure. Any insight will be greatly appreciated.