Tilt/Trim and Ignition switch does not work

[SeaHawk]

I have a 1992 Pro50 (P50TLRQ) that has electrical issues.

The outboard worked perfectly several days earlier. As of yesterday, when I turned the key to start the motor and manipulate the trim and tilt on the shifter handle, there was no power transferring to the outboard. There is no sound at all from the outboard as if there is no electrical current.

I bypassed the kill switch and still no power at the key switch. I checked the control box wiring and no visual signs of damage.

Other then that, all other electrical components on the boat is working perfectly. The trim and tilt switch on the outboard is working perfectly. I checked every electrical line for damage and or corrosion and there were none. All fuses were in working order. All brushes in the starter are clean.

An authorized Yamaha mechanic suggested the Relay Assembly (6H1-81950-00-00) might be faulty so I changed it with a new one and no cure.

My only thought on this is the main wiring harness from the outboard to the control box/key switch is the culprit. I think its unlikely because the contacts appear new on both ends with no damage/pinching on the cable housing.

Any suggestions would be very helpful as I have ran out of ideas using the Yamaha service manual.

[jb123]

you sure you have 12+ volts? check main fuses.

[SeaHawk]

Bingo, I found the problem...

I removed all electrical tape from the wiring bundles and meticulously checked each and every cable for damage and red wires for voltage. Everything checked out including the fuse except for one contact.

The red wire on the main wire harness (male connector side) had a reading of 6.7 volts. Whereas the rest of the outboard red wires were reading 12.8 volts. So I backtracked and followed a red wire from the male connector.

I found a red wire corroded from its crimp (located under bottom spark plug area). One end leads to the engine fuse and the other end leads to the outboard tilt/trim splice connector that leads to the main wire harness connector.

This explains why the manual tilt/trim and the rest of the outboard had a 12.8 voltage reading. This also explains why the tilt/trim on the shifter and the key ignition had minimal voltage and no noise when I tried to start the motor.

This repair required a waterproof splice connector and electrical tape to re-wrap the wiring bundles.