I am trying to troubleshoot my port engine. 2007 496 with DTS. Engine ran fine when I was winterizing it, disconnected battery, then re-connected it a few weeks later an then had no ignition power. Thought I missed a battery cable, and ignored it for the winter. Fast forward to now and I can't figure out where the problem is.

Engine ground is verified good, 12V at starter verified, 12V at 50A beaker (both sides) verified. Swapped ignition switches, same issue. There is no 12V on the red wire going to the ignition switch. No drive trim, beeps, or anything when key is on acc/ignition mode, and no crank. Starboard works fine.

Swapped the main relay and a few other relays side to side, didn't solve the issue. I think there are fuses somewhere, but I couldn't find any. Unfortunately there is not many wiring diagrams available. I hope something didn't take out the ecm. Anyone have any ideas/things to test and look for? No lanyards on the boat, and the lanyard circuit is visibly open, same as the other engine that works fine.

Boat is a Formula 34pc, 2007. Thanks for any help!

Shift lever in neutral?

Red/Purple wire from 50 amp breaker to ignition switch thru 20 fuse/breaker. Look for the 20 amp ignition fuse/breaker before ignition switch

Back at the boat today, I traced the red purple wire to every point on a diagram I found engine side. The three fuses look good. The shifter is in neutral, and the engine that is working well still beep with the shifter out of neutral. It seems the only thing coming forward is the can harness to the dts controllers.

I figured it out, it was the mercruiser keep alive wire that I forgot to put on that battery.

Hi, I am having exactly same issue. Can you please give me a more details about that alive wire, where is it located?

We were replacing the cylinder heads and took of the wire harness completely and I am just guessing if we didn't skip one wire, connector.

Thank you!

any ideas where the clean power harness is on 496???

where was the lead for the clean power harness?

The 496 didn't use clean power