No pre start lighting or beeps, turns over wont start

[CLARKSON]

Occasionally my starboard engine "pre igition " sequence of warning lights and double beep doesn't happen.. engine will turn over but not start...

After a few tries all is well... but today the engine stopped for no reason and took awhile to get the lights and beeps to work to start....

Port engine no problem..

I have a 2006 36 Mariner.. 6 liter fuel injected engines...
I swapped the relays on the engine with no help..
Ignition wire wires all secure and corrosion free.
Boat has no kill switch or cord...

Any ideas?????? Thanks in advance...

[ColRon]

Maybe someone with more knowledge will speak up, but could it be within the switch itself? The key on position would energize all the circuits with the exception of the Starter. The start position energizes the starter while the switch is in the start position. IF there was an intermittent short or open in the on position then the circuits wouldn't be energized, so not lights, beeps etc.

[Viper]

Ron brings up a good point and is one of the places I would begin with. If you're handy with a multi-meter, check the RUN side of the switch to ensure it's completing the circuit when you turn the key to the RUN position. Also check the engine harness plug for corroded or backed-off pins.

What are we talking about here, Mercruiser, Crusader?

[CLARKSON]

Yes. 6.0 crusader fuel injected.