Hi Everyone and Happy Thanksgiving! I have a John Deere 892 elc excavator. The old alternator had 3 wires to it . I am trying to replace it with this one wire unit from amazon- https://www.amazon.com/gp/product/B00SG0GCWQ/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 But I cannot figure out what to do with the old D+ warning light wire and the machine will not start, also when I turn the key off, it does not disengage the main power solenoid. I have to remove a battery terminal to get the main power off. I attached a pic of the back of the old one. Would anyone know how to wire this in to work? I am wondering if the machine cannot be converted to a one wire alternator? Thank you
I'm guessing you have a start relay that is controlled by the alternator current, so it won't let you engage the starter if the engine is running (and the engine is considered "running" when the D+ is not drawing current. I'd hook the D+ up to a light bulb for a little draw and see if it will start, if it doesn't start, try a bigger bulb for a bigger amp draw. No idea why the main solenoid will not disengage.
The pic i posted is of the old alternator. But I did ground the D+ terminal and the machine now works as it was supposed to except the warning lamp doesnt go out.. it is charging at about 27+ volts measured at the battery. I did put a 24 volt bulb in series so it had some kind of load on the D+ wire, but I dont know that I needed to do that. Your suggestions worked, even the main solenoid started working as it should. At some point, I need to install a volt meter so I can see if it ever quits charging. I am trying to figure out something with diodes to get the warning lamp functional. But now i have the luxury of time. Thanks for the help.
A voltmeter is better, if the wire breaks or the voltage regulator goes bad, you can have no warning light, and no charging.
Your voltage regulator inside the alternator is bad.
Mg, that's his hold alternator, the new one is a one wire so that D+ wasn't hooked to anything.
@eber Why are you replacing the alternator? Did it stop charging? Thanks Delmer, I missed that in the post. It obviously needs to be connected and I believe it should be connected to terminal 1 on a Delco?? There is an alternative. It involves a little rewiring and a relay to eliminate the alternator being an issue. Just because the alternator does not ground the wire doesn't mean the alternator is not charging. The alternator could work perfectly fine yet for some reason won't ground the blue/yellow wire to allow the monitor to shut down (which causes the no start issue as well).
Did you figure it out? Was running my excavator the other day and the battery light came on. Shut it off and now no crank. Oil light buzzer comes on and the only way to shut it off is to pull a battery cable. Would a bad alternator cause no crank?