Yanmar 1601d electrical repairs worth it?

[Chrxis1900]

I have a 1601d diesel with 1500 hours on it. This summer I have had some issues starting the tractor. I replaced the 10 year old battery and cleaned the terminals. I had lost the dummy lights and fuel/temp gauges earlier this summer, but the rpm gauge worked as did the lights, horn, and turn signals. Trying to diagnose the problem, I replaced a blown 5amp fuse. I had the ignition turned on and was tracking wires when the voltage regulator started smoking and was extremely hot. I turned off the ignition and dumped water on it to cool it off and prevent a fire. I have removed the voltage regulator and been running the tractor as needed since, always putting the battery on a trickle charger. I have since lost the rpm gauge. The 5amp fuse will blow each time the tractor is turned on however. I had a mechanical inclined friend look at it and he noted the generator has a small amount of play in the bearing. He thinks this is causing a short and is the culprit of all the problems. So am I doing permanent harm by running the tractor this way? Is it worth the expense to replace these two parts? Am I missing some other problem here? I have posted the burnt wiring harness to the voltage regulator for reference (one of two blue wires is the burnt terminal). As always thank you for looking and replying.

 

[CoyPatton]

The wiring on this is pretty simple if you understand basic wiring principles. As for your short, it could literally be anywhere.
You could replace the generator and regulator with an alternator. But iT would be a lot of rewiring. Again if you understand the basics of a 12 volt wiring system, it is nor complicated work, but very time consuming.
I believe you would find both a regulator and generator available from Hoye and others, but I believe you have an issue downstream of your 5 amp fuse.
Now the difficult part is to test find that spot as a visual inspection can become quite the chore. The difficulty resides in the path of the wires. Your issue may be a rub through of a wire, a pinched wire from other work that may have been done, a melting of wire insulation or the dreaded critters chewing on wires just to mention the most common in no given order.
If you do not feel comfortable with this work, a good electrical person will not come cheap!

 

[Roadworthy]

The slop in your generator COULD be causing the short but is not likely doing so. Coy gave some good tips for troubleshooting. Looking for the cause of the problem (bare wire, etc.) is probably less trouble than rewiring the tractor, though it would be a lot simpler to rewire than a car. If you don't do electrical work yourself you'll probably need to take it to a shop that does. Only you can balance the value of the tractor to you against what the fix will cost. A shop may charge $100 an hour but if they can fix it in a couple hours you may be money ahead. Check in with an established automotive electrical and tune up shop, not necessarily the Yanmar dealer. It will probably be less expensive and the Yanmar dealer will try to put it back to original selling you genuine Yanmar parts.

 

[HoyeTractor]

I have actually seen several of those regulators do that (go up in smoke) and all were right after jump starting or starting on a charger. They don't like that for some reason.

You won't do any damage by running without the charging system. It is risky, however, to run without a temp gauge/light and oil pressure light. I would at least install a mechanical temp gauge and oil pressure gauge if you were not going to fix the charging system. You can unplug the dynamo and see if the fuse still blows. If it still blows then you know it is not the dynamo causing the problem.

The hour meter/tachometer is purely mechanical (spinning cable running from engine to dash) so that problem is unrelated to the wiring problem.

 

[clemsonfor]

If your handy know how to wire and understand what each wire does and how it supply's signal or power to what it goes to just rewire the whole thing if you can't find the obvious offender. You can probably do it for $50 if you don't have any wire or crimp ends laying around. I could wire one up for just the cost of some different spools of wire. I already have a few colors and all the ends to do whatever I want too.

 

[clemsonfor]

I think you have a short somewhere, not the alt/generator.

The RPMs are a mechanical connection on your tractor so electronics will have no bearing on how they function.

 

[CoyPatton]

As Aaron stated the hour/RPM meter is strictly mechanical. On that mostly likely you need a new cable.

On more thought on your electrical issue the initial problem may have been the regulator and it was sending too much for your 5 amp fuse. However, by the looks of of your connector for your regulator, you may well now have issue with the wires that show signs of extreme heat/melting.
Again if you are comfortable with electrical work, check the resistance of these wires.

 

[Chrxis1900]

Thank you all for the advice and information. I unfortunately lack any knowledge of electrical systems other than hooking up the battery and putting a multimeter to it. I will try disconnecting the dynamo to see if it still blows the fuse. I can follow wires and look for damaged, disconnected, or bare wires, but short of that I wont be able to recognize any issues I'm afraid. I dont mind to replace the parts because I would prefer the tractor work properly. I was most afraid that if I replaced the regulator and dynamo there would be an underlying problem I was unaware of that would damage the new parts. I bought a tool that I was told could help. It is a couple wires with a lightbulb to check if a circuit is present. Does the ignition need to be turned to "on" or does it need to be turned completely off? I need to see what it takes to fix the rpm meter. You all reference it as an rpm/hour meter. Does this mean my tractor is not recording new hours ran currently?

 

[CoyPatton]

Chrxis1900, if you feel comfortable with a multimeter to check resistance, and to trace wires for damage, you are 80% to having the job at hand taken care of.
I would suggest the purchase of several spools of wire of various colors in 14 or 16 gauge and a variety of end connectors then go for it.
If that falls apart, I can ask my son who is in Hickory, NC area if he has any friends in east TN that could handle the electric work and try to connect you guys. I am in southeastern MO.

 

[Roadworthy]

If your tachometer is mechanical it will be connected by a cable to the engine or transmission. It will look like the speedometer cable of a sixties automobile and work pretty much the same way. If you find your generator is indeed the culprit blowing fuses, etc. it may be more cost effective to build a bracket and replace it with an automobile alternator with built in voltage regulator. It's not a difficult conversion - simpler in my mind than dealing with the old generator and voltage regulator. If your tach and hour meter are mechanical your electrical system is pretty limited - starter, lighting, glow plugs, oil light, charge light, over temp light, etc. Disconnect the generator, charge the battery, replace the fuse, look for shorted wires and bad insulation, and go from there.