no power to electric fuel pump

[oldcorvette]

I have a 2000 200hp mercury efi engine. when I turn the key on the fuel pump will not run. test procedures by manual- removed wire from neg side and jumpered to eng ground and pump ran. manual says ECU is bad. can anyone verify? should I repalce pump before I replace the very expensive ECU?

 

[alldodge]

Not an OB guy but looked up a 1999 Merc 200 and found that one side of the pump goes direct the 12V via a fuse, and the other goes to the ECU. So I would have to agree that the ECU applies a ground which turns on the pump.

That said Mercruiser does the same thing but the SCU applies a ground to a relay, and the relay is what actually turns the pump ON/OFF. The wiring diagram I looked at did not show a fuse (I assume it would have one) so it may have a relay and therefore I would look for one of them. Its would not be a high power relay, jaust a small probably square type about 1 inch square

 

[oldcorvette]

Thanks, I'll check that out.