70hp wont start, no trim tilt, no tach

[merbass101]

Hey everyone,

I've got a 1998 70hp yamaha on my 15' key largo. Boat was running great, we use it at least once a week. Then it rained here for almost 3 weeks straight. Went to use the boat yesterday and nothin happens when turning the key. The batteries fine, my neighbor showed me how to start it by shorting 2 contacts under the cowl. After starting the boat, noticed that the trim/tilt didnt work and neither did the tach. Trim/tilt works on the engine just not at the console. Any ideas? Could my ignition switch be bad, and that would cause the others not to work? Turning the key off does kill the engine, but nothing happens when trying to start it. Thanks!

[FabricGATOR]

I would open the cowl, disconnect the battery or battery switch to off.
Disconnect and then re connect the plugs and even the two (pos and neg) battery wires. Look for corroded contacts and clean as you re-connect.

Power comes up to the helm remote from the engine. Seems like your not getting power up there. Maybe a fuse inside the motor electrical box but a weeks worth of rain's probably not going to cause that. Now inadvertently shorting the wrong stuff while trying to hot wire it, that could get a fuse...

[merbass101]

Thanks fabricgator, I gonna try goin through all of the connections today.

[CatCam]

Did you check your 30 Amp fuse? I know from my 90HP the tilt and starter are on this same fuse. On the 90, Fuse is NOT located on the fuse panel but is located in a separate fuse block. Just sumptin' to check before expending a lot of time/energy on the other stuff.

[merbass101]

Just checked the 30 amp fuse under the cowl, it was fine. Unfortunately its the only fuse I can find. Any idead where the others might be? Theres no fuse panel behind the console.

[CatCam]

Yep, that's the only one. Darn, well, time to start tracing Wires & Grounds....

[merbass101]

Thanks for the help guys! Turns out I didnt have a yamaha key switch. Because of that, the wires were spliced in, rather than with a harness. The splice for the main power wire was corroded. Easy fix, but took a little time to find.

[CatCam]

Great news!! Thanks for the update and don't be a stranger! Now that you know this info on your motor you might be able to help somebody else out in the future. It is also interesting to read other issues and learn from the very knowledgeable people who help out on this forum.
Take Care,

CatCam

[FabricGATOR]

Good job Merbass101,

Yeah, splices, seawater and people not using marine grade wire.

I found on my trailer, that if I solder the wire splice with a piece of heat shrink, and before I shrink it, I inject silicon sealant into the tube. Then I apply gentle heat, exuding the extra silicon as it shrinks. That is about the best wetsplice asides from what we do offshore with the submerged cables.

Now that your an expert, maybe you can come help me fix mine...

[Pacific Fisher]

I had a similar problem and thought it was the ignition switch. After replacing that (all fuses were good), I discovered with the help of an electricion that the red 12v wire was broken or damaged in the wire harness and not delivering 12v to the switch. We completely disconnected the factory wire and ran a new red wire from the engine to the ignition switch and solved the problem.