American Thunder

Jus had the same problem on my 500efi last week. Trace wires from the relays back in the harness. U will have to untape an take off wire loom About 10in back in the harnes the power wires hook together in a connector an mine had a broken wire right there. Took a few min to get into the harness an find but it was right where Eddie said it would be lol

norton

Fixed it! After unwrapping the ecm, fuse, and both relay harnesses only to find all wires and connectors in great shape---no breaks or pulled wires, etc., I finally got smart and did what I should have done a week ago. Turned the ignition on and started wiggling all wires everywhere to see if I could cause a connection. Wiggled the starboard ignition wiring plug (the 1.5 inch round rubber connector) and low and behold-- the fuel pump activated. Removed the plug and determined no broken wires or connector; inserted it very firmly and tightened the plug hose clamp-- Good to go.

Thanks very much for all who responded for the help and suggestions!!!

Young Performance

I assume you are talking about the cannon plug (10 pin main harness plug)? If so, pull it back apart so you can spread the pins. Each pin is actually made of 3 parts. You can insert a small pick or screwdriver into the end of the pin and it will spread them apart some. That will give them some tension in the receptacle. It's pretty common for them to get compressed over time, especially from cranking down on the hose clamp that holds the plug. It should not be super tight. It's just there to stop the plug from falling out.
Eddie

lear60man

Necro post. Im having the same issue with my Gen VI 502 MPI. Background: Boat has been sitting for a few months while getting a new engine (port side). Ran it home and the starboard motor cut out and died. Put it in neutral and it re-started it successfully. Short ride home no problem. Went to start it to flush it and no power to cool fuel pump (no buzzing when you move the key to first position). Applied 12v on the bench (good test). Swapped fuel relays with stbd side and no change. Checked the three fuses under the cap, all good. On the helm there is a 'Dual Batt' switch to use both batteries in case you run one down, you can start the other motor using both batteries. Well.....I hit the switch and I could hear the pump buzzing when I turned the key like normal. The 'Dual Battery' switch is on the same panel as the ignition switch so Im thinking it would be prudent to tear into that first light? Might pick up another ignition switch as that might be the culprit? Low voltage on one the Stbd battery? Aliens?