John Deere 125 blowing diode to coils??

[cbs123]

Hi Guys,

A customer of mine asked me about the diodes on the kill wires of a JD 125 with kohler engine. He says they are located close to the coils on the motor, on the kill wires. One per coil right after the kill wire Y or fork.

He says he bought a 10 pack of diodes off the internet and has been carefully replacing them with heat shrink, yadda yadda. Says it will crank and run fine THREE times, then the 4th time, the diodes are blown and he has to do it again.

Any suggestions?

 

[StarTech]

First if the diodes are properly size it shouldn't happening; unless, there is a massive feedback voltage. Second the 125 came a v-twin Briggs and not a Kohler so if it is Kohler we would need the engine numbers but most twin cylinder Kohler coils have the diodes built into the coils.

 

[ILENGINE]

Faulty key switch or intermittent short backfeeding 12 volts to the kill wire

 

[StarTech]

Faulty key switch or intermittent short backfeeding 12 volts to the kill wire

12VDC should not be blowing 200 PIV diodes; although, I prefer to use 1000PIV diodes but voltage from the coil can blow those cheap diodes as you are sinking several hundred volts so forward voltage rating needs take this into account.