# Starting problem John Deer F 525



## sarazwork (Sep 11, 2012)

I'm helping problem solve a John Deer riding mower F 525. Front deck lawn mower.

It doesn't start. You are probably saying, "Well, there is your problem." 

I am pretty sure that the problem is in the wiring harness somewhere. 

Some durn fool cut a lot of wires and then reconnected them. What a mess....!

When I initially checked the connections, I found one miswired block which I corrected. It immediately started up and hasn't started since. 

There is power to the key. The starter is good, battery is good, the ignition switch is good, the blocks are all good, the fuses are all good, the safeties seem to look fine. I can't find any obvious breaks in the visible wires.

The only thing I can think of to do is take the whole wiring harness apart and do an inch by inch look for breaks in that.

I have half of the wiring diagram. 

Anyone have a checklist for doing a point by point electrical test on each system to trouble shoot this puppy?

Sara


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## Country Boy (Mar 18, 2010)

By not starting, I assume you mean doesn't crank over when you turn the key. If that is the case, I generally start by bypassing all the safeties one by one until I have them all bypassed, trying to start it after each bypass. If that fails, then I check for continuity on each wire from one connection to the next, ie from the key to the seat switch, then to the relay, then to the starter solenoid, etc. If you find a wire that you don't have continuity on, then you probably have found your issue. Most multimeters have a continuity setting where they will beep if there is continuity when you touch the probes to each end of the wire in question. I'd also look for a complete wiring diagram for the unit so you can follow the layout better.

If the unit cranks but won't start, then I'd check the trigger module for the ignition coil. They are known to fail and are easy to replace. They bolt to the block somewhere and have a wire running to the ignition coil. The ones from Deere are pretty expensive, but aftermarket ones do work as I have used them in the past.

I'll move this thread to the John Deere mower section. You'll probably get more eyes viewing it that way.


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