Adding lights to a JD 4010

Its hard to know how the light wiring was cobbled in the change. In theory with the original having a +12 and a -12 circuit where the lights needed to be matched to keep the two loads balanced, as far as the lights and accessories were concerned it was only necessary to connect the two power input leads (to the ignition and light switch) together and to the remaining +12 volts terminal on the starter solenoid. But that means keeping those original switches with two independent circuits switched simultaneously.

The original generator was only rated at 10 amps, likely it took at least half a day to charge the batteries after a start and that's without running any lights. The alternator should be more like 50 amps and handle a significant number of added lights. Though if there's airconditioning for the cab that clutch and fan motor will consume 15 to 20 amps.

A circuit diagram should be very similar to that of the gas 4010 or early 4020 without the ignition stuff and with a negative ground.

Light power would come from the battery terminal on the starter solenoid through a self resetting circuit breaker mounted on the kick panel near the "ignition" switch. It would go to the auxiliary input on that switch and that auxiliary output would feed the light switch. Since it was a 24 volt diesel there were two such circuits originally, one positive and one negative with respect to ground.

Gerald J.

As for the lights, get a multimeter and check the terminals on the light switch. If they are putting out 12 volts in the correct position, them just connect a new, longer wire to a good portion of the existing harness.

As to powering the accessories in the cab I would use a Bosch style relay. To clean up the wiring I would look for a fuse block also. These parts should be available at a good automotive parts store. I would try to mount them on some sheet metal in the cab on the front left side. The relay should have a wiring diagram on it.

Wire the relay as follows. Run a heavy wire, say 10 ga. between the + cable on the starter and the power in wire on the relay. Run another heavy wire from the normally open output terminal of the relay to the input of the fuse block. One of the two other two terminals on the relay needs a wire to ground. The final wire must be hooked to a wire or terminal that has 12 volts only when the key switch is on. Make sure that any wires that have to go through sheet metal openings have extra protection such as flexible loom. You could also drill a hole and use a rubber grommet. The idea is to prevent the insulation from wearing out and causing a short.

Run wires from the fuse block to the various cab accessories. Hopefully with a good 12 Volt source they will work again.

Good Luck

John

The relay and sturdy will will make the cab stuff work like it never has before.

Gerald J.

John