JD 355 diesel lawn mower - electrical problem

[Hay Farmer]

I've got a JD 355 diesel mower and amongst its many problems, there are now no dashboard lights when you turn the ignition key. Needless to say, it won't start, but that I can fix later.

The battery has 12.5 volts and the headlights work.

I've traced power to the ignition switch, turn the key on one position and you get power on the 2nd red wire which goes to the ignition control module thing. There are a 2 more wires connected to the ignition switch, yellow and white, and they never have any power to them. There are two 15 amp fuses on the control module and they both have approx. 12.3 volts on both sides.

In the maze of wiring at the control module there are two red removable plug things each on two wires - no power to these either.

I'm a bit stumped for what to do next, nothing is obviously chewed or damaged.

Any ideas or advice apart from teaching it a permanent lesson with a 10b sledge hammer?

Cheers.

 

[Exfarmer]

Get the battery charged up first 12.5 is on the low side, or try jumping it, but it may be solenoid somewhere

 

[itsalwaysme]

Get the battery charged up first 12.5 is on the low side, or try jumping it, but it may be solenoid somewhere

12.5 volts doesn't sound too bad does it, what would you expect

 

[itsalwaysme]

I've got a JD 355 diesel mower and amongst its many problems, there are now no dashboard lights when you turn the ignition key. Needless to say, it won't start, but that I can fix later.

The battery has 12.5 volts and the headlights work.

I've traced power to the ignition switch, turn the key on one position and you get power on the 2nd red wire which goes to the ignition control module thing. There are a 2 more wires connected to the ignition switch, yellow and white, and they never have any power to them. There are two 15 amp fuses on the control module and they both have approx. 12.3 volts on both sides.

In the maze of wiring at the control module there are two red removable plug things each on two wires - no power to these either.

I'm a bit stumped for what to do next, nothing is obviously chewed or damaged.

Any ideas or advice apart from teaching it a permanent lesson with a 10b sledge hammer?

Cheers.

Are you sure it's not an inhibitor switch somewhere

 

[Hay Farmer]

It might be, it's just that I assumed the dash lights would come on when you turn the key initially, and that any inhibitor switch would just stop it from trying to start when you turned the key further?

 

[itsalwaysme]

It might be, it's just that I assumed the dash lights would come on when you turn the key initially, and that any inhibitor switch would just stop it from trying to start when you turned the key further?

I'm not familiar with the model so not sure about the lights coming on, (do you have instruction manual) The first thing I would check would be inhibitors though

 

[Dave W]

Assume by inhibitors you mean seat switches etc?
In which case there are usually 2 circuits. One stops the engine from cranking if the pto is on or handbrake not engaged etc.
The other circuit cuts the engine if the seat switch isn’t pressed without handbrake on or pto in neutral.
Neither circuit would stop the dashboard lights coming on.
Try shorting the starter to see if it will turn over. That will tell you if the battery has power and you have an earth.

 

[Mursal]

So you have absolutely nothing working on the key, so should be an easy fix

It should indeed turn on, I'd imagine ...........
Take the module off and take it in to the radiator for the night.
Visual check the pins on the plugs for green/black corrosion?

You need to load the wires with a bulb to see if you loose the voltage due to a bad connection?
Just connect as you did the meter
Especially the other end of the wire coming off the ON position on the key.
Just follow the colour

 

[Hay Farmer]

Assume by inhibitors you mean seat switches etc?
In which case there are usually 2 circuits. One stops the engine from cranking if the pto is on or handbrake not engaged etc.
The other circuit cuts the engine if the seat switch isn’t pressed without handbrake on or pto in neutral.
Neither circuit would stop the dashboard lights coming on.

Try shorting the starter to see if it will turn over. That will tell you if the battery has power and you have an earth.

There's power at the starter motor, and the earth is good.

So you have absolutely nothing working on the key, so should be an easy fix

It should indeed turn on, I'd imagine ...........
Take the module off and take it in to the radiator for the night.
Visual check the pins on the plugs for green/black corrosion?

You need to load the wires with a bulb to see if you loose the voltage due to a bad connection?
Just connect as you did the meter
Especially the other end of the wire coming off the ON position on the key.
Just follow the colour

Thanks Mursal, I'll try that tonight.

 

[Dave W]

Have you tried jump leads or different battery?
I’ve known duff batteries to be showing 12v but be knackered

 

[Hay Farmer]

Have you tried jump leads or different battery?
I’ve known duff batteries to be showing 12v but be knackered

There's enough power for the headlights to work, i'm not trying to start it at the moment - just want the dash lights working. It's a fairly old battery, and possibly does need replacing to start the engine.