How do I check whether my tractor alternator is working

[Coyote machine]

Yes, belt tension could be part of the problem; it's a good idea to check it whenever you have the hood open. It should deflect about 1/2" at the middle of the span between the alternator pulley and the water pump pulley. If you can rotate it in place enough to see the underside it should NOT look/be glazed like an Easter ham! It should not squeal like a pig at a pig roast either!
If it's glazed or has chunks missing or it has visible cracks, replace it and keep a spare, just in case for future use. Better to have one on hand if an old one breaks in either sub-zero or 101+ degree weather, miles from the barn, right?
External voltage regulators usually have a plug in harness with 3-4 wires which match what goes to the alternator. Sometimes they're hardwired with no connector at the regulator. They're usually on the firewall or fairly close to the alternator.

Internal v. regs are usually a small separate unit/black box built into the back of the alternator, near where the wires exit. If the shop checked the alternator properly they would have also checked the v.reg, if built into the alternator.

Does anyone have a wiring diagram for this model tractor?

 

[Soundguy]

alt repair and sales shops must LOVE you.

that is HORRIBLE advice.

disconnecting an alternator unloads it and can make damaging voltage spikes.

kinda like slapping a baby till it quits crying. may work.. but is BAD!

it is exceedingly easy to use a CHEAP 15$ amterage guage , a VOM and a test lamp to 100% troublesoot that system.

the test lamp is used inline with bat hot post, machine off, to check for leakage and small shorts.

The leakage in the diodes in some (or all) alternators is said to slowly discharge your battery.

If the machine is running and you turn on lights, does the motor change it's tone? If it does, it means the alternator is making power.

If you have access to a clamp on meter that does DC (rather expensive) it can be a great trouble shooting tool.

Does this machine have an integral voltage regulator in the alternator or seperate? If you say the alternator tested good, maybe it's the vr.

EDIT: I guess another simple (tool less) check would be to start the thing, turn on the lights and disconnect the battery. See if the lights stay on. Watch that the battery leads don't short on something.

 

[Soundguy]

the turning on the lamps listening for a load on the engine may work on a lawnmower.. but for stock lamps on a 4600.. a beefy machine.. i don't think you'd hear ANY difference.

 

[Soundguy]

ps.. for those interested.. my manual says the regulator is D7NN10316B

 

[diesel lover]

My thinking would be on the firewall. Sorry, I never knew their was a risk of blowing the diodes in your alternator by removing the battery while running. You say you don't have a dash mounted ammeter, but you must have an idiot light, no? Is it on? Does it come on when you turn on the key, but before you start the engine?

Its OK industrial toys. We all make mistakes. I learned bad habits from the wrong people and through two tech schools and my full time job At a truck shop I know now what's right from wrong. We all make mistakes we all learn

 

[Coyote machine]

alt repair and sales shops must LOVE you.

that is HORRIBLE advice.

disconnecting an alternator unloads it and can make damaging voltage spikes.

kinda like slapping a baby till it quits crying. may work.. but is BAD!

it is exceedingly easy to use a CHEAP 15$ amterage guage , a VOM and a test lamp to 100% troublesoot that system.

the test lamp is used inline with bat hot post, machine off, to check for leakage and small shorts.

The poster apologized one page back after I said to never disconnect the cables when the engine is running. :confused3:

The OP was/is looking for how to troubleshoot his alternator, charging system. You gave a part number for the alternator - do you know if it has an internal V. reg?

Do you have a wiring diagram for his tractor?

 

[Soundguy]

The OP was/is looking for how to troubleshoot his alternator, charging system. You gave a part number for the alternator - do you know if it has an internal V. reg?

Do you have a wiring diagram for his tractor?

i gave the part number for the REGULATOR.

and anyone can hit the NH parts site and get a good idea of the wireing layout looking at the exploded diagrams in the electrical section.

there is a left and right side.

plus you have the alts listed depending on the market and variant.

 

[Coyote machine]

I missed the note of the part number being for the regulator, sorry. Good to know about the NH site for the OP and others too.
Thanks for the info.

CM

 

[tommyboy1]

My tractor has the idiot light and it does light up when I turn the ignition key just before starting the engine.

 

[Dave M7040]

This link will show you what the regulator looks like. In your case it is a likely suspect since your alternator was checked, however, you could have damaged the alternator by accident and now have both a bad regulator and alternator.
Dave M7040

Ford Tractor Voltage Regulator - D7NN10316B