2420D Electrical gremlins. No start.

[qualityhardware]

Thank you all gentlemen. Internal/hidden corrosion makes great sense. I am tasking cable replacement for the high amp connections. A 43 year-old harness from SE Asia might have an issue or two lurking. Will report.

 

[careyo63]

Thought it was odd looking. I think they actually call it a Denki Alt.. Don't see them very often if at all in the US.. Knew that looked different and sure enough! Maybe a problem there?

Alternator - Denki Style (20670) fits Yanmar YM226 YM1510 YM1601 YM1610 YM1702 YM1802 YM1810 YM2002 YM2010 YM2220 YM2310 YM2402 YM2420 121450-77200

Alternator - Denki Style (20670) for Yanmar Tractor(s) YM140, YM147, YM169, YM180, YM186, YM187, YM220, YM226, YM250, YM276, YM1401, YM1502, YM1510, YM1601, YM1602, YM1610. Replaces Yanmar OEM Number(s) 121450-77200, Replaces Yanmar Mfg Number(s) 20670.

www.tractorpartsasap.com

 

[qualityhardware]

Update, gentlemen. Thank you all for the input. I am happy to report success. I did the following:

• Replaced the old battery cables with new, 2 gauge wires
• Replaced all the old fuses, cleaned all the fuse contacts inside and outside the fuse box
• Cleaned the connectors of the light switch, turn signal switch, and horn switch under the dash

The results are:

• The tractor runs reliably for the first time in six months
• The turn signals work
• The horn works
• The main lights don't work and I think a new light switch is in order
• I also nuked the set screw on the light switch knob, even after soaking in in Liquid Wrench for 30 minutes. The metal (brass?) was too soft and it stripped right out

Added bonus:

• Take the extra two minutes to remove your shear bolt from the drive shaft and gear box connection on your bush hog, remove your drive shaft from your bush hog, and store it in the nice, dry indoors if you won't be bush hogging for several months. It saves you a couple of hours of hard labor with a come-along, chains, Liquid Wrench, scotch pads, and lube of every kind to restore your drive shaft to working order.

Photo below of the old wires and battery clamps. In the close up of old battery clamps, you can see the rust and corrosion. In addition, the fit of the bolts through the clamps was not flush. Note the interior diameter. There had to be anywhere from 1/16" to 1/8" of gap between the bolt and the internal wall of the clamp, which may have provided an opportunity for some arcing. Who knows?

 

[bmaverick]

Update, gentlemen. Thank you all for the input. I am happy to report success. I did the following:

• Replaced the old battery cables with new, 2 gauge wires
• Replaced all the old fuses, cleaned all the fuse contacts inside and outside the fuse box
• Cleaned the connectors of the light switch, turn signal switch, and horn switch under the dash

The results are:

• The tractor runs reliably for the first time in six months
• The turn signals work
• The horn works
• The main lights don't work and I think a new light switch is in order
• I also nuked the set screw on the light switch knob, even after soaking in in Liquid Wrench for 30 minutes. The metal (brass?) was too soft and it stripped right out

Added bonus:

• Take the extra two minutes to remove your shear bolt from the drive shaft and gear box connection on your bush hog, remove your drive shaft from your bush hog, and store it in the nice, dry indoors if you won't be bush hogging for several months. It saves you a couple of hours of hard labor with a come-along, chains, Liquid Wrench, scotch pads, and lube of every kind to restore your drive shaft to working order.

Photo below of the old wires and battery clamps. In the close up of old battery clamps, you can see the rust and corrosion. In addition, the fit of the bolts through the clamps was not flush. Note the interior diameter. There had to be anywhere from 1/16" to 1/8" of gap between the bolt and the internal wall of the clamp, which may have provided an opportunity for some arcing. Who knows?

This is how to clean and carefully take apart the headlight switch.

Headlamps flickering then quit working, finally solved.

Most of the YM series, both domestically sold and gray market have the Stanley headlamps and Yushin-Seiki switch. I had spend about 2-hours debugging the failed light. The bulbs are the halogen type Wagner HM202 that are the direct replacements of the Stanley P15D25 incandescent. The...

www.tractorbynet.com

 

[etpm]

Thanks for the update. It looks like a bad connection was indeed the culprit.
Eric