I own a Scag STT61V-29DFI Turf Tiger....Kawasaki 29HP motor. (I’m new to engine troubleshooting so excuse any incorrect wording). I can’t get my mower to run without hot wiring it. Fuel Pump works great when hot wired, but not getting power to the fuel pump from fuel pump relay without the hot wire. I’m stumped. There is 12v going into the fuel pump relay at the top 87pin, there’s 12v registering on the right #87 pin of the relay (which is piggy backing off of the 87 pin I just mentioned), there’s 12 volts on the left pin #86 ( The wiring diagram says this goes to the engine), BUT there is NO power on the bottom pin (#30) which goes directly to the fuel pump. Like I said, I can attach a hot wire from anywhere registering 12v ( whether that’s the battery itself or any of the hot pins I just mentioned) to the 30pin which runs to the fuel pump or even the 87a pin in the middle, and the fuel pump turns on and allows me to mow. I tried replacement relays, but it’s always the same problem, no power getting to the 30 pin or the 87a pin. If I take the relay off and plug it into the main relay jacket right next to the fuel pump relay, this relay makes the clicking sound to show it is working properly. But none of the relays I have are making the clicking sound when I plug them into the fuel pump relay jacket. All of the wires are clean and making good contact inside the jacket that the fuel pump relay connects into. Any ideas as to what is keeping Power from moving that 1 centimeter over to the 30 pin or 87a pin? I don’t think it is a relay problem. Could it be the electronic control module (Denso 21175-2059)? Would there be something within this module telling the relay not to provide power to the fuel pump?
Last edited: