Mercury Optimax motor to Yamaha Harness and controls

[Matt1309]

I bought a 2005 Ranger Z21 that was rigged with a Yamaha VMax motor. The boat didn’t have the motor when I bought it and I purchased an Optimax 250 from my buddy.

The boat has all the Yamaha controls and harness still in the boat. I have an older Mercury control box with the 14 pin harness, but it’s missing the part of the harness for all the gauges. Is it possible to cut the 14 pin harness end off and splice it into the Yamaha harness?

I know I would have to make sure the correct wires are connected since Yamaha and Mercury use different colors, but is there any disadvantage of doing this?

Is there anyone who has done this that could tell me what 4 wires will be left over after splicing? What do they control?

Before anyone says just buy a mercury harness and swap it out. I cant afford a brand new one right now and I haven’t found one close enough on marketplace at a decent price.

thank you in advance for your help and knowledge!

[Jim Speros]

Welcome to the site Matt, You are starting down a tough path trying to get the two systems to co exist. Before you further butcher what you have consider purchasing an engine that matches the boats rigging or save to purchase the matching harnesses and gauges for the merc.

[Greg G]

I have a fully rebuilt Vmax 250 HPDI spare motor that I would sell you and then you sell the Opti. Welcome to S&F !!

[Matt1309]

I appreciate the suggestions. Buying a new motor just isn't an option right now and I wasn't sure how difficult of a task this would be. I just assumed it would be fairly easy to cut and splice as long as the correct wires were matched with one another.

[Matt1309]

Thanks Greg, I don't have the funds to buy another motor right now and I'm more of a mercury man anyways haha.

[Greg G]

I gotcha. Be super careful on trying to make one adapt to the other. Electrical gremlins be the toughest to deal with as you know.

[Jim Speros]

. I just assumed it would be fairly easy to cut and splice as long as the correct wires were matched with one another.

Its not that simple. You are putting expensive electronic parts at risk.

I would be surprised if anyone suggests you proceed on this path.

[paragod]

I bought a 2005 Ranger Z21 that was rigged with a Yamaha VMax motor. The boat didn’t have the motor when I bought it and I purchased an Optimax 250 from my buddy.

The boat has all the Yamaha controls and harness still in the boat. I have an older Mercury control box with the 14 pin harness, but it’s missing the part of the harness for all the gauges. Is it possible to cut the 14 pin harness end off and splice it into the Yamaha harness?

I know I would have to make sure the correct wires are connected since Yamaha and Mercury use different colors, but is there any disadvantage of doing this?

Is there anyone who has done this that could tell me what 4 wires will be left over after splicing? What do they control?

Before anyone says just buy a mercury harness and swap it out. I cant afford a brand new one right now and I haven’t found one close enough on marketplace at a decent price.

thank you in advance for your help and knowledge!

did you ever get this idea to work ?