Yanmar 4JH2 wiring harness

[Alii]

My 1997 4JH2E with 9500 hours has the C engine panel. On the engine end of the wiring harness running from the panel (part # 129573-77930) there are 3 plastic clip connectors that reside right under the hot exhaust elbow. About one out of 10 tries the starter will not engage unless I pull these connectors apart and spray them with CRC. Is there anything special inside these plastic connectors (1997-ish nano-technology?) or are they simple, mechanical connections? Is it safe to cut out these old plastic pieces and join the wires together directly with butt connectors? I would think so, but thought I should ask before I cut and crimp.

[geoffr]

Originally Posted by Alii

My 1997 4JH2E with 9500 hours has the C engine panel. On the engine end of the wiring harness running from the panel (part # 129573-77930) there are 3 plastic clip connectors that reside right under the hot exhaust elbow. About one out of 10 tries the starter will not engage unless I pull these connectors apart and spray them with CRC. Is there anything special inside these plastic connectors (1997-ish nano-technology?) or are they simple, mechanical connections? Is it safe to cut out these old plastic pieces and join the wires together directly with butt connectors? I would think so, but thought I should ask before I cut and crimp.

Nothing special in them. I'm just installing a YM30 and I have wondered about the poor quality of the wiring loom... be sure to seal up the crimps after so you don't need to fix again later.
I'll be keeping my connectors but will wrap in rescue tape.

[Alii]

Thank you, geoffr. My two main parts guys in Singapore and Cal also confirmed there is nothing special about these plastic bits. Will use Ancor heat-shrink connectors and extra wraps of Rescue Tape.

[boatbod]

They are "waterproof" Deutch connectors in a really awful location. Common problem unfortunately, but the fix is easy. Just cut them out and splice the wires with waterproof butt connectors.

[NoTies]

If my memory serves me correctly, as well as the 3 multi plugs there is also a single wire bullet connection. This bullet connection is not as moisture proof as the multi plugs and is the signal wire for the start solenoid relay.

[pcmm]

Originally Posted by NoTies

If my memory serves me correctly, as well as the 3 multi plugs there is also a single wire bullet connection. This bullet connection is not as moisture proof as the multi plugs and is the signal wire for the start solenoid relay.

Close, the single wire is for the STOP solenoid relay. I just replaced my dead perkins 4-154 with a rebuilt 4JH2E this summer and the stop soleniod was there, but the wiring for it on the engine was missing. the single wire connection was wired to the stop button on the engine panel (factory new engine panel)

the connectors, if point down towards the engine mounts should be far enough away from the exhaust to not get more than mildly warm. the problem as I see it is in most installs, the engine wiring harness probably goes up, keeping the connectors closer to the heat of the exhaust. the connectors really would have been better placed closer to the center of the engine above the starter solenoid.

[boatbod]

It's not so much a heat problem as water leaks from the exhaust elbow.

[Alii]

My connectors are immediately under the exhaust elbow and the problem is heat -- I don't have any leaks, never any water in the engine pan. Having removed the old plastic bits with fresh butt connectors and heat shrink, the starter now pipes right up. It must have always been starved for current before. Sounds much healthier now.