I ordered the relay kit (AM107421) and received it today. The instructions are for Kawasaki. Does anyone have instructions for a JD 1050? I might be able to figure it out if I had a schematic, but don't have one. Any help would be greatly appreciated. Thanks. Ron
As I mentioned above in my post from 3 years ago, I added the relay kit to a JD 750 that I used to have. I can't say for certain if the 750 and the 1050 are the same electrically as far as the starter/solenoid in the starter circuit are concerned, but I will tell you how I did it, and what I know about it. The assumption here is that your starter motor has the solenoid integrated within it. I don't have a schematic or wiring diagram I can send you, so I will just have to describe it here. I believe all the connection points for the new relay kit should be directly on or pretty near the starter motor.
Going by memory here, there are 4 wires to connect. Two wires will connect to the coil of the new relay, one wire will go to ground, and the other wire will go to the wire on the starter/solenoid that comes from the ignition keyswitch. You want the coil on the new relay kit to energize whenever you turn the ignition key switch to the crank position. One terminal on your new relay may be marked (+), that will go to the wire that comes from the keyswitch. The other lead should be marked (-), it will go to ground.
The second pair of wires will connect to a set of NO (normally open) contacts on the relay. Not having seen your relay, I can't know if it has just one set of contacts, or multiple sets. The NO set is what you want to use, though, and if that's all it has it should be simple enough.
One of these two wires from the NO contacts will connect to the heavy gauge 12V+ wire on the starter, this 12V+ heavy gauge wire should come from the battery (probably through the fusible link). The fourth wire on the new relay will connect to the terminal on the starter that energizes the solenoid. Yes, this is the same wire that comes from the keyswitch (that you already connected one wire too).
Here's why it should help it crank better... the existing circuit that provides 12V+ to the starter solenoid on the starter motor uses wiring that is slightly undersized, and it goes through several connection points (which can corrode over time). This undersized wiring and all the connection points create resistance in the circuit. If you know anything about Ohm's law, you will understand that this resistance will create voltage drops, and tend to limit the current to the solenoid coil by a slight amount. Since diesels have higher compression, they need more torque from the starter motor, even more so when it's cold. Adding this extra relay provides a more direct 12+ volt connection from the battery to the solenoid, thus helping to overcome the voltage drops, which helps the starter solenoid.
One last point, you do not want the heavy current coming from the battery that go through the solenoid contacts to the starter motor going directly through the contacts on this new relay. If so, it will probably burn up the contacts pretty quick. If that happens, then you have wired it up wrong. Good luck.
