Long 460: Smoking Voltage Regulator?

[Aegis07]

I recently inherited the upkeep of my Dad's Long 460. I was filling it with diesel the other day and noticed smoke coming up between the fill lid and the firewall. I traced it back to the engine side of the firewall and found a small smoking box on the engine side of the firewall. It stopped smoking shortly thereafter. If you turn the key to accessory it doesn't smoke at all. Turn the key to the run position and it starts to smoke after a minute or two and will smoke a minute or two after the tractor is turned off.

The tractor is out of service pending my doing some repairs on it. I looked at the attached wiring diagram that I have for the 360 series and I think from the position and the wires coming into the box it is the voltage regulator. I checked over the wires coming in to the voltage regulator and I see no charring or other wiring issues. I gave the rest of the wiring a once over as best as I can and I see no wiring issues.

So my three questions are:
1) Am I right that this is the voltage regulator?

2) I found a few options for replacement regulators:
a) Amazon.com: TISCO - NO:TX12129.VOLTAGE REGULATOR LONG:35, 36, 445, 46, 51,& 61. 12 V...: Industrial & Scientific
b) https://www.ebay.com/i/283457490431...9XF4223LbtakwZZCygmi1aZBesOKBIbBoCgOsQAvD_BwE
c)TX12129 - Voltage Regulator for Long Tractors | Up to 6% off Dealer Prices | TractorJoe.com

Any thoughts on what is the best one to go with?

3) How concerned should I be that this is some wiring issue that I am missing that is burning it up? Or is it just as likely that the 38 year old part may have just decided to give up the ghost at this time?

Thanks for any answers!

 

[Roadworthy]

The smoke box could indeed be the voltage regulator. You could probably trace a couple of wire to see for sure. You COULD have an insulation breakdown over time allowing something to short and over heat. It's also possible there's a problem elsewhere and the voltage is trying to compensate. Some voltage regulators are made to be opened so adjustments can be made. If yours is one of these you may be able to look inside. All that would do is confirm something is overheating but not necessarily tell you why - other than you may see what's breaking down. In short, I can't troubleshoot from here and replacing the voltage regulator makes about as much sense as anything for a first step. You could check the output voltage to the battery to see if it's trying to overcharge the battery. Be sure the alternator is putting out DC. They generally make AC and have internal diodes to turn it into DC. Just a thought.

 

[Old Guy in Tenn]

The regulator may normally get hot as it works, and there may be something dripping onto it that is getting cooked off by the normal regulator heat. Look for contaminates spilling on the regulator before deciding that the regulator is bad.

 

[k0ua]

Check the battery for charging voltage. When my regulator in my 2360 Long failed (do to loose wiring on the regulator) it cooked 2 batteries and split them with 17 volts charging voltage. Caused excess gassing in the batteries and made small splits in them. This caused acid to leak onto the metal battery box floor. Lots of rust. The voltage coming out of an unregulated alternator is about 17 volts depending on RPM. That is why a voltage regulator is required. Of course modern alternators have built in regulators instead of and external box.

 

[Wagtail]

I would be very cautious trusting any electrical/electronic device after it has got so hot as to 'smoke'.

Insulation may have 'broken down', resistor/diode integrity/specification may be compromised.

 

[CoyPatton]

Before replacing,
1) it looks quite greasy in the pictures, it is possible that the heat (normal for older regulators) may be burning off some of that grease. Being 38 yrs old, it will be not withstand a hard washing. Spray a degreaser on a rag and wipe it down very well. Then follow up with a tooth brush and degreaser (again do not spray the regulator, but dip the brush into the cleaner or spray the brush.
2) unplug each wire from the regulator (if you have not) and check the condition of the connector, its cover, the actual wire and the connector on the regulator. If the regulator connector appears discolored going into the regulator and you can not open the regulator, replace the regulator. If any part of the wire seems damaged, trace that wire, looking for damage to the wire as well as damage to whatever it connects to.
3) check your battery—is it charged? Is it being over charged?

 

[rScotty]

Yes, it's the voltage regulator. You can tell because you can see the ends of the typical wire-wound resistors. Yes, they can run hot enough to melt metal if something is going wrong inside.....and especially if your battery is good. Yes, one instance of smoking that means they are done, although they can be rebuilt - although it is a chore - and it saves a day to have the specs on that particular VR. BTW, there are usually are holes in the bottom (side in photo) that you cannot see where wired go through to connect the ww resistors to the internal relays. If you try to wash it you are likely to get water inside it.

If you decide to replace it you will be offered two types of VR. There is a remanufactured old style type like yours in a hollow steel box containing relays... and a newer semi-conductor type that is a flatter device and all encapsulated in epoxy. Unfortunatey it is hard to find a quality VR these days. They are all built overseas with low price as most important.
If you can find an old OEM part at some dealer ... one that has sat on the shelf for 20 years .... that would be my first choice. In fact, far and away my first choice even if he wanted twice the price for it. Second choice would be a new version of the old hollow can, third the encapsulated semiconductor type VR.

Electrical things that smoke always are always shot.
rScotty