860 Wiring Diagram - 12v conversion

It may be best if you look at the tractor and explain to us how it is wired to see if something is wrong and draining the battery.

But if you are looking to rewire it I can give you 2 wiring diagrams that will work on a 800.

800 12V with one way diode
800 12V with car key switch
How to convert to 12V

I charged the battery and the tractor started right up. I put a volt meter across the battery terminals, and it was only reading 12.4 volts, so I guess its not charging.

I took another look at the wiring to the key switch: it has 4 terminals: IGN (which goes directly to the coil), Batt (connected to the battery side of the relay), ST, which is the sole connected wire to the relay's left most small terminal, and Acc (which is not connected to anything).

But, I'm still a bit confused. I have combination of what was in John's post: a single terminal alternator with a 4-post car type key switch. Is my probably that the alternator is not getting energized to start charging enough? Is the alternator shot completely? Or is it that the connections aren't right? Note that there is no diode in this circuit, but the key switch's Acc is n't connected either.??

thanks for any tips,
Stephen

Alternator-is a Delco Remy. It has a single lug terminal to which 3 wires are connected: One wire goes into an opening in the alternator itself and appears to be have JBWeld smeared all into the hole, so I can't tell what its connected to inside. The other 2 wires connect back to the relay.

Relay-while looking at the tractor from left to right: Left-most is the big terminal connected to the starter with a large gauge cable. Next is a small terminal that is connected to the 4-terminal car key switch. Next is the other small terminal that is connected to one of the Alternator wires. Finally, the right-most big terminal is connected to 3 things: the other alternator wire, a large gauge cable running to the battery, and a cable running to the key switch.

Note that the relay appears to be new and shiny, so I'm wondering if someone might have installed the wrong one. There are no markings on the relay. Is there any way to tell if its appropriate? I'm guessing based on your notes that the right-most small terminal is probably the Acc terminal and that the 2nd wire from the Alternator is going to that, but not sure.

Key Switch-4 terminal car type (you have to turn the key to complete the ignition circuit). The key switch Acc terminal is not connected to anything. Note that I disconnected the ammeter and light switch when I got the tractor (they didn't work), and also, there was no terminal block. The key switch is connected directly to the coil.

Thanks for the help and any additional comments. I'm gonna try to get out there and charge that battery to see if it'll start. Then I can check the voltage to see if its getting charged or not. Gonna have minor back surgery on Wednesday; I've been having some disc problems, so let's see how much I can get done.

thanks again,
stephen

#2 is VR sense line.. it can loop down to the charge stud.

#1 Excite line for field. It needs to go to either:
:a 914 bulb then to the switched side of your ignition.
:to an isolated accy lug on a automotive type ignition switch.. though ideally you still include the 914 bulb in line to protect the vr.
: thru a diode capable of carrying a few amps then to the switched side of the ignition switch. Cathode end of diode toward alternator..

Easy to check with a vom if your system is charging. 12.6v or lower is battery in some state of discharge. 13.8-14.7 ( ideally 14.4-14.7 ) is a battery charging.

Your ammeter should be showing net charge or discharge to the battery... A negative deflection means there is no charge, and battery is supplying ignition power. A positive deflection denotes battery charging or charged, and ignition draw is being offset by alternator.

all lods are wired on one side of the ammeter.. and the line to the battery on the other side.. this way you can measure net charge / discharge.

Soundguy

From previous posts the Vintage site is undergoing some changes and hasn"t been up for a while. Don"t know when it will be back. Perhaps someone else does. Regarding 12 volt diagram, if you"ll do a search in the archives of this site there are many posts about it. Find the one from John in LA and I think you"ll find the diagram you need.