Triad to Command Wiring

[Bill725]

Starting to get parts ready to swap the Kohler Triad engine in my Sovereign to Command. Not to hard mechanically but what about electrically. Can someone provide some insight?

[PhanDad]

The following is an except from my Sovereign "Triad to Command" post in the Tech Tips section of the site. I don't believe you have access to it unless you're a club member. It probably has more info than you want:Next is to get the tractor wired for the Command. First some reference diagrams. The Simplicity Sovereign OHC wiring diagram from the 2001 Large Frame Repair Manual:

The Kohler wiring diagram for a Command:

I added the "internal engine" wire that goes from the Command connector plug to the starter solenoid on the Command starter. The 4 "external" connections are shown around the connector plug:Ignition Module Input (engine kill wire - ground)Starter and Carburetor Solenoid Input (start circuit)B+ and Carburetor Solenoid Input (+12v "run" circuit)Oil Pressure Safety Input (for oil pressure light, etc - optional)Besides the "control" wiring shown in the above diagram, a main +12v power heavy gauge wire must be connected to the Command starter. It is recommended that this wire come directly from the battery. The corrected Simplicity Sovereign Command (OHV) wiring diagram from the 2001 Large Frame Repair Manual:

The "correction" is the main +12v battery cable; the Command OEM cable (Simplicity #1708730) runs directly to the Command starter and a pigtail lead from the battery connector supplies +12v to the tractor as can be seen in the electrical parts schematic for a Sovereign with a Command:

However many conversions use the existing heavy gauge "start" cable that went to the Triad starter (but wired differently as documented by BLT and is described later). First a general pic of the inside of the "Triad" dash tower after the battery and gas tank have been removed:

A closeup of the dash solenoid "Triad" wiring:

There are 3 main power wires connected to the solenoid: On the left post, the main battery lead (large diameter wire) and the tractor +12V feed (smaller wire that goes to the circuit breaker)On the right post, the "start" cable that went to the Triad starter. To make the minimum wiring changes and maximum use of existing wires, just move the Triad heavy gauge original "start" wire to the left terminal:

The right post will be wired with a new light gauge "start" circuit wire (more on this later). The above wiring modifications are shown in BLT's marked up Sovereign OHC wiring diagram:

The red marking shows the moved heavy gauge starter wire and the blue is the new "start" wire.The issue with the above wiring setup is there is an extra connection in the main power wire to the Command starter. Al Eden told me the Command starter is susceptible to low voltage failure; that's why the OEM Command wiring +12v battery cable runs directly to the Command starter and has a pigtail lead that provides +12v to the rest of the tractor.IMO, another issue with the late model Sovereign wiring is the lack of the +12v distribution board that allows easy hookup of accessories (hour meter, snow blower spout rotators, snow cab lights or wiper, etc). My choice is OEM Command +12v battery cable with a 7100 series power distribution board installed. First dismount the interlock relay, circuit breaker, ignition switch wiring connector and unwire the solenoid load side posts:

Prepare the distribution board (Simplicity #1665230):

Besides the "stand-off" washers used to keep the connector mounting rivets (on the backside of the board) from contacting the side of the dash tower, I put a full face plastic insulator against the dash tower.The holes are still in the side of the dash tower to mount the board:

Mount the board, circuit breaker, and interlock module:

The interlock module is mounted using just 1 bolt (as OEM) to an existing hole just under the hydro lever safety switch. (Later in the process when I went to connect the interlock module to the wiring harness, I decided it was better to reverse the module mounting so that the wires were pointing up and toward the dash tower. I had to expand the mounting hole to 1/4" since only the OEM bolt side had been enlarged) The OEM Command +12v battery cable shown as designed to be installed:

Note the "push on" connector on the pigtail. Since the wiring harness is different for a Command, the Command OEM +12v battery cable can not be used without changing out the wiring harness or making wiring modifications to allow use of the existing harness. (In the Command electrical parts schematic shown above you can see wires from the harness connecting to both power side solenoid posts as compared to the Triad wiring.)I make the necessary wiring modifications so I can use the existing harness; here's a pic of the new/revised +12v wiring I use:

The top wire in the pic is the original wire from the battery side of the solenoid post to the circuit breaker; I just added some shrink wrap to the solenoid connector end. The second wire (from the top) is the pigtail from the battery; I cut off the "push" connector and added a 5/16" ring connector. The third wire is the new "switched +12v feed" wire (ignition switch "L" terminal to the +12v distribution board).The fourth wire is the new "start" wire (dash solenoid to starter solenoid) which has a 5/16" ring connector on one end. Here's a close up of the ignition switch end of the "switched +12v feed" wire:

The female wiring disconnect (Kohler #2545201) has a barb to hold it in the plastic ignition switch connector. The other end has a standard female wiring disconnect since it will be connected to the distribution board. I solder all the disconnects, especially the harness connector types since I don't have a tool that crimps them on "factory style". For a primer on how to remove wires from the ignition switch connector, see BLT's U-tube video:https://www.youtube.com/watch?v=SwDSl6B4crw&list=UUqqYykGUxY3mSx4Vi-OLTEg&index=7I use a small flat blade screw driver as the removal tool. Remove the red/blue trace wire from the ignition switch harness connector:

Insert the new "switched +12v feed" wire into the ignition switch connector (end with barbed disconnect):

Connect the other end of the new "switched +12v feed" wire from the ignition switch and the red/blue trace wire (removed from the ignition connector) to the distribution board:

Connect the wires to the solenoid load side posts:

The battery pigtail and solenoid-to-circuit breaker wires are connected to the left post. The new "starter" wire is connected to the right post.Connect the solenoid-to-circuit breaker wire to the circuit breaker:

An overall pic of the modified +12v wiring:

The last wiring task is the tractor wiring harness connection to the Command. And of course there is an issue.The Command connector:

The tractor wiring harness connector:

Both connectors are the same gender (female disconnects). The solution is to change one to the matching connector (Kohler #2515506) with male disconnects with side barb and rear guide tabs (Kohler #5245201)

Here's Al Eden's "pin out" diagram (with my additions) for the connector:

 

It shows the tractor connector being changed; that is the easiest since there are only 2 single wires in the "Triad" harness connector. I recommend the same.A pic of the new male disconnect installed on the +12v red/blue trace wire:

Note the disconnect is soldered. Then install the disconnect into the new connector:

Do the same for the white "kill" wire and the new "start" wire and the wiring modifications are done unless you want to wire the Oil Sentry (if your Command has one). Here's a pic of the engine connector mounted on the side of the engine (the holes are already in the engine tin):

The above pic is the Command in my 1st 75th Anniversary tractor (I reinstalled it as the PO hacked the original install). You can see I wired the Oil Sentry into the engine "kill" circuit by connecting the Oil Sentry pin back to the magneto kill circuit (white wire loop); if the engine oil pressure is low, the engine shuts down. (The Oil Sentry "switch" is normally grounded when the oil pressure is low; when there is adequate oil pressure the switch opens removing the ground.) I also put a manual disconnect in the white wire loop so I could easily disable the "low oil pressure" engine shutdown feature. Although the above "low oil pressure" engine shutdown feature is easily wired and protects the engine without having to watch for a "low oil pressure light", there is an issue: When starting the engine, there is no oil pressure and hence no spark. The engine has to crank awhile for the oil pressure to build enough to remove the ground and allow spark. So for this install, I decided to use one of BLT's "magic" relays. Here's his relay wiring schematic for using an "old style Kohler" ignition switch (+12v to coil) to provide a ground "kill circuit" for a magneto engine:

For my needs, the pins are connected as follows:#86 engine start wire #85 ground#30 Oil Sentry #87A engine "kill" Pins 30 and 87A are normally closed contacts. This means when there is NO +12v to the start wire (ignition switch "off" or "run" positions) pins 30 and 87A are connected; the Oil Sentry is connected to the "kill" circuit and will shutdown the engine on low oil pressure. When the start circuit is energized, the contacts will open and the Oil Sentry will NOT be connected to the "kill" circuit and the engine can start immediately. Some pics:

In the above pic, the top male disconnect has a single white wire for the Oil Sentry, the middle disconnect has 2 red wires for the "start" circuit, and the bottom disconnect has 2 white wires for the "kill circuit".

I bought a new relay at an auto parts store since I wanted one with a mounting ear, it's a "Standard RY48" relay.

 

August 10, 2019 Update:  I replaced Al's Figure 13, "Simplicity Sovereign TH to Command" drawing - replacement has added detail for wire #3.  Tom Howard noticed the wire stripe was different - plug vs table.   

Edited August 11, 2019 by PhanDad
Replaced Al's Figure 13, "Simplicity Sovereign TH to Command" drawing.