4320 gen light

Just replaced both batteries and the battery cables on my 4320. Also had the alternator off and took to a shop and they checked it cleaned it and said it was operating fine started the tractor and it shows charging at like 14.6 on both batteries but the gen light still glows lightly in the dash and it drives me nuts. My 4020 and 3010,s lights all go off but this one is still glowing any ideas?
 
Cornerpost is right, I fought one too and local dealer says its common and not to worry about it. I did replace the alternator a year later with a Delco and the factory harness(pigtail for a 7520 4wd) and the light still glowed the same as with the Motorola. Don't sweat the petty stuff, and don't pet the sweaty stuff. chris
 
"Normal for it to glow a little."

Yes, up to a point. He can check the voltage at the alternator output stud, the (+) post on the battery, and at the "always hot" battery terminal of the "ignition" switch while it's charging, and any significant different in voltage between any of those three points will make the indicator glow brighter. (Caused by a dirty or poor connection in the charging and power supply to the key switch circuit.)

Otherwise, it's related to voltage drop across the isolation diode(s) at the Motorola alternator.
 
I agree with the others, it is common. I have installed a diode in the light circuit on several to eliminate the glow. It comes from a voltage drop in the wiring where the voltage from the alternator on the light wire is higher than the key switch voltage feeding the light. The light by design lights when there is voltage differential but in this case is lighting for the wrong reason.
 
Any common diode capable of carrying a couple of Amps will work. I keep 1N5408's on hand, 3 Amps, 1000 PRV, and CHEAP to buy in quantities of 100 on ebay.

The idea is the diode creates a forward voltage drop of about .6 Volts, taking that much away from the glowing lamp, but still allowing the lamp to light if the alternator actually fails.

Another solution is to simply install a Delco 10si or 12si alternator. I just did that recently on a 4620 that smoked it's Motorola alt, and for the first time in years the lamp doesn't glow dimly.
 
The delcos are one wire alternators correct? How would I hook that up to mine since I have the main stud but also two other wires coming out of it that go to the gen light?
 
No, the Delcos are NOT "one-wire" alternators.

It's just the aftermarket bastardizations of them that are.

Jumper the #2 terminal to the output stud, and connect the wire from the "idiot light" in the dash to the alternator's #1 terminal, and all will be well.
 
I always wondered why the gen light on my 4420 combine would glow a bit in a dark shed. But you can't see it in the daytime. According to what I read on this thread, that is normal on some alternators. Thanks for the good information. Al
 
Just an update I put a diode in line to the light and it works perfect light comes on and once started goes completely out. The only diode I had was rated at 1 amp but it's working I plan on getting a three amp and putting it in. Thanks for the help
 

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