I need some help with my voltage regulator. I bought a 330 yanmar diesel and the wires from the regulator are melted. Do I really need to replace the entire wiring harness as the guy at JD dealer said or is this common and there is a easy fix?
It can be fixed -- usually the burned wiring on the regulator (and any attendant regulator failure...) is due to high currents from trying to charge a battery that has a shorted cell or otherwise is beyond the end of its useful life. Look for melted contacts in the disconnect going to the alternator as well, as heavy current can damage those as well. Once the contacts get overheated they lose their spring force, raising the resistance of the connection and causing further heating. The TM1591 has the wiring diagrams of the Yanmar engined tractors. Here is an excerpt:
Thanks Chuck, I've included a picture of the regulator and wires as I got it. We bought a new house with about 3 acres and I got a 317 and am using it and happy with it but found a guy locally with this 330 with snowblower and blade attachments, he seemed to have little knowledge of the equipment and was the only owner of it. I gave $600 for all of it and figured if I could find a way to fix it and I'd have a heck of a deal. To my understanding and from reading some information on here this is a great tractor and the yanmar is super durable and dependable little diesel. I have a new regulator on he way and will try splicing the wires and fixing it. Now I know I may want to put a new battery in too!
You can still buy the red wire and you can shorten the alternator wires and put the new plug closer to the alt. The other wires you could splice up higher in the harness but make sure you get ALL the damage out or a short can do more damage and ruin new parts. You can still buy the alternator connectors and voltage regulator connection. That is the worst I have seen one. Fyi- don't put a JD battery in. And that is a GREAT price you paid.
I've gone to my local JD dealer and they said they can't get either plug, I need a whole harness (I can't see that!). Yay suggestions where to find them? I thought of spade connectors and heat shrinking them to remake the connections. Thanks for all the help!
The most important part of the repair is to ensure you have replaced all the heat damaged wire as the oxidized sections will have a much higher resistance and just get hot again. Also, be sure to make a good, gas-tight crimp so the terminals are reliably connected to the wire ends -- a quality ratchet-style crimping tool is the best choice. Here is a picture of mine for the insulated splices and terminals, another tool with a separate set of dies is needed for the bare terminals that insert into the block housings. Some more costly tools have interchangeable die sets.
Thanks for all the help! I got it running today, I soldered and used heat shrink on all my connections, did them wire for wire checking each wire by stripping it back until I got clean wire (no corrosion). Now when I run it after about a minute at WOT the battery light flickers. I thought maybe the alternator took a hit when the regulator burnt up but then when I turn the headlights on the battery light goes out. I'm 100% positive the wires are hooked up just as they came off. Any suggestions?
Might be a poor ground somewhere, or the regulator did get a bit damaged. Also look for a voltage drop from the battery terminal voltage to the green sense lead of the regulator (this is where the relay kit is needed to avoid "boiling" the battery electrolyte...) The regulator needs to "see" the battery terminal voltage well enough so it does not try to charge an already fully charged battery -- and any voltage drop in this connection will cause a false sense of battery condition.
Here is some data from Deere on the modification...later model regulators than those available when the 330 were in production are temperature compensated as well.
Thanks Chuck! I'll check my voltage and see where I'm at. I bought a new (aftermarket) regulator and put it on when I fixed the wiring. I'm wondering if it being a cheaper regulator than the John Deere one could be an issue as well. I ran the tractor around the yard for a few minutes just to see how it did and I'm absolutely in love! I left the headlights on and the battery light stayed off but eventually, even with the lights on, it slowly started to come back on. I took it to my garage, removed the side panel, checked the wiring and it all appeared to be fine and not heated up at all. I've put in a new regulator, repaired the wires and replaced the voltage regulator so far but still chasing that one little demon with the light. It's odd to me that at start up there are no lights at all then the longer it runs the more I get the light! The little diesel is impressive, it made me not even want to look at my 317 again!
Ok, I'm checking voltage at the regulator with everything hooked up and this is what I'm getting:Red wire 14.81Blue (alternator) .40-.56 fluctuatingBlue (alternator) .49-.65 fluctuatingBrown 7.35 - 7.50Green 14.58At the battery 14.46
The two yellow/white wires are AC voltage from the alternator -- a meter on a DC setting will not give a consistent reading from ground, you should measure across the pair on an AC setting.
The 0.14 volt delta from the green sense wire compared to the battery voltage is a bit puzzling in that the red wire at 14.81 volts connects directly to large terminal on the solenoid at the starter (hence it is at the other end of the very heavy positive battery cable...) and given that the battery positive should be HIGHER than the green wire if anything...since the F4 fusible link, the key switch, the 10 amp F2 fuse and multiple wire spans are in series with the green wire as voltage travels from that same starter/solenoid terminal. It really is not much of a delta, so it may not result in electrolyte boiling if it were actually reversed in magnitude any. Either 14.46 or 14.58 each indicate that your battery is fully charged.
The brown wire from the regulator is what drives the dash lamp, and at 7.5 volts it would indeed be dimly lit.
Checking voltage voltage at the regulator across the two yellow wires on AC setting I'm getting 13.9 volts at idle cold startup. If I increase RPM's to WOT I'm getting 21.3 until almost a minute of running then the battery light begins to flicker ans I'm at 31.9 volts WOT. If I turn the headlights on and draw some power the battery light goes out and naturally the voltage drops however after another minute or so the voltage slowly increases to 31.9 volts and the light comes back on flickering. Would it be safe to assume I'm getting an overcharge from the alternator caused by the original burnt wire and voltage regulator or that the overcharge caused the original problem? I guess I'm asking if you think my alternator is the demon in this mess I have? Thank you for all your knowledge and help. I'm new to these tractors but fell in love immediately! I have a 317 and a 330 and I'm considering selling my 317 since this 330 should do everything I need done and I love the diesel power!
Won't the AC system change with RPM? Doesn't the voltage regulator do the regulating based on what the green wire gets in vs what it needs to send out? I don't know enough about AC electricity when the generator isn't constant speed. Maybe I am thinking hertz and not volts.
I understand it will rise but to what voltage? Also that doesn't explain why my battery light comes on after running for a minute or so or the higher voltage at the green wire causing the light. I don't want to cause more damage but I want to use this machine asap
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