Ferguson TE20 - converted to 12V with a generator?

[Waudby]

Hey folks,

I have acquired a pretty straight TE20 that needs rewiring among a couple other things. The wiring is pretty cobbled together. I have rewired a TEA20 before (12V one-wire alt) so it's familiar enough erritory. However, this one has some things going on that are unusual to me.

The system as it is wired is 12V positive ground. The battery (12V top post) shows 11.6V not running. Starter spins with no trouble (I suspect likely still 6V starter, so 11.6V should spin it well). The ignition coil has been replaced with a 12V coil marked no external resistor needed. Primary coil resistance is 3.5 Ohms which is in the normal range as far as I know. There is no ballast resistor in the circuit I can find, just many, many butt connectors...

There is still an original style voltage regulator wired into the circuit, and an original looking generator. I think the system is charging as I've run it for over 10 hours without any issue. While running, the voltage holds right around 11.6V, so perhaps it isn't charging? It was my understanding that a generator had to be rewound to charge 12V and the VR replaced, but perhaps this has occurred? (Or perhaps the previous owner, who knew little about the machine and apparently bought it off someone who "fixed it up", was misinformed?)

My question is, since the battery voltage seems low, is there something funny going on here with the generator and voltage regulator? As I plan to use this a dolled-up working tractor and not a full on restoration, would I be better off just to swap in a one-wire alternator? Appreciate any thoughts or feedback. Cheers.

 

[Jim L WA]

Hi Waudby, welcome to the forum. Interesting what your found.
Going the 1 wire alternator rout is what I would do.

 

[Tomindallas]

I'm with Jim on this. The average battery should run about 12.6V idle. While running, the alternator should show output voltage around 13.5V at the battery in the normal healthy system. If the system is showing less than 12v at the battery while it's running, it's likely the ignition is running off the battery.

My TO 20 was doing the exact same thing when I bought it, even though it had been converted. Basically running off the battery. I found the alternator's regulator wires weren't even connected. It was lucky for me just a simple matter to correct it.

 

[Bruce(OR)]

Uh... w h u t ?
*
12.6V is the battery voltage NOT running.
Running with the GM 10si alternator typically produces battery voltage from 13.2V to 14.5V at idle. You could
run as high as 15.5V or perhaps as low as 13.0V.
Those being GM numbers.
However, 12.6 is a universal number for the static battery charge.
This is why it is possible to check alternator output with the engine running.
12.6 on a charged battery with the engine not running and once the engine starts, the battery voltage should
rise up to the typical 13.2V to 14.5V If the voltage does NOT rise up or is out of spec, you *might* have a
charging problem and further diagnosis might be needed.

 

[Steve@Advance]

If you need dependability over originality, then convert it to an alternator.

The biggest problem with generator systems is the poor quality of aftermarket regulators.

A 6v generator can be made to work with 12v. If the tag on the generator is black, it is 6v, red is 12v.

Someone may have intentionally adjusted the regulator down if it is trying to charge but at a lower
voltage. That may make a slight difference in saving the starter from hitting the flywheel so hard.

Be careful with the starter once it is fully charging. They slam the flywheel hard when operated on 12v.
It can strip teeth, break the nose cone, or push the ring gear back off the flywheel. Always be sure the
engine is fully stopped before engaging the starter, not rebounding off a compression stroke. Keep the
engine well tuned for easy starts. And plan ahead so to limit unnecessary starts and stops.

 

[Waudby]

(quoted from post at 11:05:36 12/13/23)
Be careful with the starter once it is fully charging. They slam the flywheel hard when operated on 12v.

Funny you should say that Steve - part of the reason I got a good deal on this machine is that there are several stripped spots on the ring gear, and as a result it doesn't reliably start depending on where in the rotation the engine stops. The previous owner didn't have the ability to split it, but it's on my winter to do list.

So it seems that someone has indeed "converted" it to 12V but left the original 6V starter. I have a local source for replacement 12V starters so that will have to be added to the list of parts.

If someone has turned the VR down, I would imagine the battery would be consistently undercharged as well, possibly contributing to reduced battery life?

What I'm hearing is confirming my initial thoughts that someone has cobbled on this unit and then sold it as "12V conversion". So it definitely seems like I will be going the alternator route, which cleans up the wiring slightly as well. The starter was already going to need servicing as the armature has substantially more end play than I think it should; is there supposed to be a retaining clip on the inside of the nose cone to stop the armature from sliding forward? I don't mean the bendix, I mean the entire armature slops back and forth inside the starter housing, a good half inch plus, which seems like a lot and has probably contributed to the flywheel wear (or been caused by it).

I'll have to check the generator to see if there is an indicator tag on it, but regardless I think it will be replaced.

Appreciate all the feedback. This has helped as I was pretty confused as to what was going on with this unit.

 

[Fergster]

It's easy enough to run a 12volt positive ground generator and regulator if that's what you want to do. Full field the generator to make sure it's charging 13 volts plus. Make sure you have a12 volts regulator and uts wired right. Don't forget to polarize it. Ofcourse you can't beat a one wire gm alternator

 

[Tim PloughNman Daley RIP]

Hi Waudby, welcome to the forum. Interesting what your found.
Going the 1 wire alternator rout is what I would do.

System will operate on POS or NEG system. 12V/NEG GRN is the norm. Understand what the GEN and VOLTAGE REGULATOR are and what an ALTERNATOR is and looks like. The 1-Wire DELCO 10-SI Unit works well on a 12V Conversion. No VR is used in the 12V conversion circuit; external 1.5 OHM resistor only required if using OEM 6-V Coil. No other Ballast Resistor in the circuit. Fan Belt tensioner required regardless if using a GEN or and ALT. Not going to charge the battery without it. Decide if you are going to use the OEM 6V/POS GRN system or do a 12V conversion job. Your local ALT/GEN Shop cans test and rebuild the GEN. Get proper manuals and wiring all verified is correct B4 proceeding to start up. Use correct wires and cables.

Tim Daley (MI)

 

[Bruce(OR)]

and the inline diode. . .

 

[Jim.ME]

and the inline diode. . .

He posted he has a generator and regulator, and it appears he is trying to get them working properly. No alternator involved at this time (the alternator conversion he mentioned was a different tractor).