New Scag wiring harness issue with Kawasaki engine

[Omer55]

Hello, I'm new to the forum here and thought I'd see if someone might could help me out. I posted this in the Kawasaki forum as well, since I wasn't sure which forum this applies.

Helping a friend install a new wiring harness that got torn up on his Scag turf tiger with a Kawasaki FD791D engine.

No spark getting to plugs. While we had the key on, the connector to the coil starting smoking getting hot. We found there to be 12volts on the coil wire of both coils. My understanding is these wires to the coil are for the "kill" circuit that allows you to shut your engine off. So I believe there should not be 12 volts on these wires.

Checked a know good Scag (same model and engine) and we only got .4 volts on the wire going to the coil.

I'm thinking there may be a wire crossed or something on this new Scag harness we got.

Looking on the wiring diagram (link below page 7-5) The number one plug coil wire goes to the key switch, and the number two plug wire goes to the ECM module. However there appears to be what looks like a diode symbol with a rectangular box above it between the number two coil wire and the ECM. I don't know what exactly that is or where it is at. Anyone have any suggestions? I'm thinking if its a diode, it may be leaking or installed backwards allowing 12 volts to the coils.

We also swapped the ECM modules, but no change.

http://www.kawasaki.com/kengine/Enginesecure/ServiceManuals/FD711D.pdf

 

[mechanic mark]

FD791D Kawasaki is diesel engine, no spark plugs, injectors. Post all numbers from engine data plate. If engine has spark plugs, wrong wiring harness.

Request Rejected click anyway,see if this helps after retrieving serial number from mower. Scag wiring diagrams included as well as part numbers.

 

[Omer55]

This is definitely a gas engine, Kawasaki FD791D (DFI). The wiring diagram shows the spark plugs and coils. I think the manual shows several different models listed.

http://www.kawasaki.com/kengine/Enginesecure/ServiceManuals/FD711D.pdf

What looked like diodes in the diagram I believe are simply spade connectors. We got 12 volts going to our coil wires which shouldn't be there. Since all the connectors on this harness are keyed and unique, there doesn't appear to be any what it could be connected wrong. We're thinking maybe one of the plug connectors are pinned wrong from the factory.

If that's the case, we've got a lot of troubleshooting left to do.

 

[Omer55]

Looks like we found a connector from the harness to the engine was installed backwards, or "upside down". While this plug was keyed, we management to plug it in ok without realizing it. That what was causing the 12 volts being shown down the line to our coils.

After looking thru the the factory service manual, which appeared to be much different that the Kawasaki manual showed, we found the connector that was the culprit. Reversed the connecter and problem solved. We did however have to replace the coils in both of them.