1969 2520 alternator problem

[2520-4010]

When I turn on the key, the alternator light should shine....right?

Well, mine doesn't. I have power to the alternator (the big red wires) but no power going to the alternator light. It is the original alternator (Motorola, I think) and I would like to keep the tractor original as possible.

What should I be looking for?? Something in the alternator?

Thanks for all replies and help!!

 

[Roger in Iowa]

Have you checked the bulb? Is it burnt out?

 

[wore out]

One side of the lamp should have power with the key ''ON'' and the other side of the lamp is connected via the wiring harness to a wire coming out of the voltage regulator.

 

[2520-4010]

That's the deal....neither wire is hot at the indicator bulb.

 

[Jim.ME]

(quoted from post at 16:59:14 09/17/22)
That's the deal....neither wire is hot at the indicator bulb.

Power to one wire of the light, before the engine is started, comes from the ignition side of the switch (or circuit powered from there). The second wire goes to the alternator to excite it. Power through the bulb makes the bulb light with the alternator acting as ground. Once the alternator starts charging it provides power back to the switch, "canceling" the ground so the light goes out. You need to find out why the light isn't receiving power from the switch to start with.

 

[2520-4010]

Have you got a wiring diagram for a 2520??

This is a motorola alternator and I've got a tech manual and unless I'm reading the schematic wrong, both
wires coming from the alternator go to the indicator light. One orange and one blue.
I'm not doubting your info.....just can't seem to figure out what's going on.
If you have a wiring diagram, could you please check it out.

Thanks in advance!

PS. This is a 1969 model....before serial #19542.

 

[Jim.ME]

(quoted from post at 18:08:34 09/17/22)
Have you got a wiring diagram for a 2520??

This is a motorola alternator and I've got a tech manual and unless I'm reading the schematic wrong, both
wires coming from the alternator go to the indicator light. One orange and one blue.
I'm not doubting your info.....just can't seem to figure out what's going on.
If you have a wiring diagram, could you please check it out.

Thanks in advance!

PS. This is a 1969 model....before serial #19542.

I do not have a 2520 wiring diagram. How about posting a legible picture of the one you are looking at?

 

[2520-4010]

https://drive.google.com/file/d/1pcW8-0Q6gtM3M7dnHj714vZlSZ8yARRT/view?usp=sharing

 

[2520-4010]

better pic of the wiring diagram....purple wire and orange wire from the alternator.

 

[Jim.ME]

(quoted from post at 09:53:42 09/18/22) https://drive.google.com/file/d/1pcW8-0Q6gtM3M7dnHj714vZlSZ8yARRT/view?usp=sharing

Follow DKBL-7 from the Key switch. That wire provides the initial power to the indicator light, through a diode. The O-4 and PU-3 have no power when the alternator is stopped, the key switch has to provide that power to start things. You could have a bad connection at the switch or in a connector.

 

[2520-4010]

Thanks!
I will check out the connections. I've already checked the switch
and had power there.

Again, thanks for getting me on the right trail!!!

 

[2520-4010]

No luck so far....I have power at the
switch.
What would the diode look like? Or
could it be one of the circuit breakers??
Thanks for all the help....someone has
painted and the wires are hard to
identify as to color with these old eyes.

 

[Jim.ME]

(quoted from post at 20:21:19 09/25/22)
No luck so far....I have power at the
switch.
What would the diode look like? Or
could it be one of the circuit breakers??
Thanks for all the help....someone has
painted and the wires are hard to
identify as to color with these old eyes.

It is likely the diode will just appear as a small spliced, bump in the wire. The power has to get from the switch to the indicator light to start things.

"I have power at the switch" only tells me you have power to the battery terminal of the ignition switch. That would say the fuses/circuit breakers are ok. If in doubt, check the continuity of a fuse or test to see that both terminals of a circuit breaker have power.

When the key is turned on, do you have power on the correct terminal of the switch to go out to the indicator light, as shown in the schematic? If so, you need to follow that DKBL-7 wire to find where it loses power before reaching the indicator light. Plug in connectors are suspect locations.