Good Monday all.

New to me Merc 496s are installed and were running great. Went on 2 week business trip and now Port motor does nothing when I turn the key....no click, no fuel pump...squat! It acts like the "Breaker" on the front of the motor has popped but when I push on it - there is no reset.

While gone there was rain and battery got down to 75% per my smart charger. Each motor is connected to it's own bilge pump (with an in-line fuse). Recharged battery to 12.5 when I returned. Also have 2 bilges connected to house battery bank which solar keeps topped off.

Battery at 12.5v
12.5 at starter and both sides of starter fuse.
Ground wire from battery replaced and "roughed up" where it touches block.
Replaced terminators on positive starter wire from battery as well.

Batteries are a two years old - sealed deep cycles. Are the 496s super sensitive to battery type or something?

Thanks for suggestions!

Neutral safety switch? Kill switch?

good question. Boat has neither one - oooolllddd school

The 496s are sensitive to voltage, not neccessarily battery type. They don't like low voltage.

Check to see if you have 12 volts from the purple wire coming off the ignition switch with key in on/run position.

Power going into your ign switch ? Is there power going out when key is turned to on and start ?

Thanks for the suggestions Gents! I will check tonight .... as mentioned I didnt use it for 2 weeks and batteries did drop and get recharged. I should have thought of the purple wire and ignition switch itself (ass- oomed)

Oddly - I found some new info and thought I would add to this:

1) Batteries are good and getting 12+ to purple wire
2) Replaced ignition switch as she was corroded and ancient
3) Worked for a few weeks and then....starter worked but key on and no fuel pump
4) Found a one bad fuse out of three in the little fuse thing.
5) Everything worked well for 2 weekends and then ... nogo

I am thinking the rough idle and electrical issues are related. I hear that a Fuel Pump Relay can get flakey and do weird intermittent things.

ANYONE know which of the three Relays are for the Fuel pump? Also - do I have to use Merc part or cam I pick up a few at autoparts store?

Thanks!

Intermittency makes me think its a corrosion related issue.. Have you tried unplugging the main engine harness plug and checking for corrosion or looseness? While its unplugged, you might want to take a small flat head screwdriver and try "widening" the plugs a little to make sure they are making a good connection with the receptacle side.

Thanks Aship - will try this later today. I picked up 4 fuel pump relays and will also try those.