john deere 750 electrical

arbtmn

Member
I recently began rewiring my tractor with NO electrical experience. Ha! My goal was to get rid of the key and install a push button starter, my own engine gauges, etc. Well I had some trouble figuring out how to start the tractor after I rewired some stuff but finally got her cranked. My problem now is I do not know how to charge the battery through the alternator. I understand the two wires from the alternator go the the voltage regulator. Can I run a wire from the VR back to the black terminal wire on the starter or the battery terminal itself? Or the positive terminal? To confuse matters, the battery terminals are backwards. In other words the red positive side of the battery is grounded to the tractor frame and the negative terminal wire goes to the starter.
 
FIRST of all... that tractor is DEFINITELY supposed to be (-) ground.

It is POSSIBLE the battery is charged backwards (YES, that can happen).

Try this... connect a multimeter to the batter, black lead to battery (-), red lead to battery (+)... if the battery is charged backwards, the pointer on an analog meter will deflect downwards, a digital meter will show a (-) ahead of the volt reading.

If the battery IS charged backwards, power the headlights overnite to completely drain the battery, then recharge with the correct polarity.

It is IMPERATIVE to get the battery/ground polarity correct (negative ground) BEFORE going any further with the charging system.

The regulator will be destroyed if the polarity is backwards, which (from your previous posts) may have happened already.

Is is DEFINITELY possible to connect up the charging system to your simple/revamped wiring, but we need to know more about the regulator/rectifier.

There's 2 leads for AC from the alternator, a ground lead, a lead that sends charging output to the battery, probably a lead that's powered when the "ignition" switch is "ON", and a lead to the "idiot light".

We have to identify all those wires to make this work, and I don't have a "750" manual, nor have a been able (so far) to come up with a diagram on the 'bet that would identify the regulator connections.
 
ok I will work on this. While the battery is hooked up backwards meaning the positive is going to the tractor frame i recall placing my volt meter positive to positive and neg to neg and I Did Not have a minus sign on the volt meter.
 
(quoted from post at 09:27:42 08/28/18) ok I will work on this. While the battery is hooked up backwards meaning the positive is going to the tractor frame i recall placing my volt meter positive to positive and neg to neg and I Did Not have a minus sign on the volt meter.

OK, so the battery is charged correctly, but connected up backwards.

We discussed this before, but how many wires in the voltage regulator connector/

Is there also a separate (ground) wire with an eyelet terminal?
 
maybe this will help, I have a PDF of the Technical manual you're welcome to, shoot me your email
if wanted

Joe

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Hello. So to recap, all I wanted to do was to get rid of the old wiring harness and lights powered by AC current. If I need lights I will use battery powered magnetic led lights and this will be quite rare. So all I need the Voltage Regulator for is to charge the battery at the proper voltage. So how can I do this? can I run a wire from one of the vacant terminals of the voltage regulator (2 terminals being used for the 2 wire alternater) and go to the positive post on the starter? Will this work anyone? Bu the way, I did burn up my new regulator with the reverse polarity on the battery and I have another one on the way.
 
(quoted from post at 07:37:11 08/31/18)
All I wanted to do was to get rid of the old wiring harness and lights powered by AC current. All I need the Voltage Regulator for is to charge the battery at the proper voltage.

To be correct, lights were powered by DC current.

As to the regulator, connect the two blue wires to alternator.

Connect red wire (charge output) to battery cable terminal at starter solenoid.

Black wire goes to a good chassis ground.

Connect the yellow wire to switched power that shuts off when the key switch is turned to "OFF", and comes on when the key switch is turned to "ON".

If you want the charge indicator light to work, connect the green wire to one side of the lamp, and the other side to chassis ground.
 
Thank you for that Mr. Bob. I think this would do it. I will be using a push to start button switch and toggle switches that i believe will work per your instructions. Will give it a shot. Thanks a bunch
 
Hello again. Well I put it all back together. I scrapped the plastic instrument panel and made an aluminum one with new gauges, a master switch and a momentary starter button. I runs and starts well. So in reading the post above regarding the voltage regulated I realized that i DID NOT connect the black wire to chassis ground This is probably why I see almost no increase in voltage to the battery when it is running. As far as my oil pressure and water temp gauges, I have them hooked up (they are the electrical type) but the pressure gauge pegs out when I apply power to it and the temp gauge does not measure anything. They have power and I am thinking that both senders are bad from the tractor? Maybe the senders are not for gauges like I put on the tractor being they just emit a signal for a light and not a gauge?
 

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