D17 won't start

I am having problems with my D17 starting. It has been running well for the last year or so, but then I started having problems. It started with the tractor being hard to start after it was running for a while. Then it progressed to being hard to start all the time. And now it won't turn over. It makes a click sound and that it is. Things I have replaced: alternator, starter, starter solenoid, positive and negative battery cables, cable from solenoid to starter, and the battery. It doesn't turn over at all. I took the starter off and turned the ignition and the starter turned. I did try to bypass the solenoids but got the same click sound.

Where should I go from here?

Ampprobe: Expensive item. If you have an electrician friend have him check the amp draw on the battery cable going to the starter when you try to start the engine. Without knowing the specs for the starter I would guess you should see a 200 to 450 amp load initially going to the starter.

Pull the spark plugs. Attach the battery charger to the battery. Set the charger in the jump start position. Try starting the engine.

A guess. If the starter turns when you have it out of the tractor, everything is wired correctly. It takes quite a number of amps for the starter to turn over the engine. I'd guess the battery is the problem. If you had a loose connection, you should see or hear arcing.

Try jacking up a wheel. Could be that one or more pistons are badly scored. Let's hope not.

Electrical wiring and connections. Double check the wiring to see that everything is wired properly and that the battery cables are on the right terminals. Battery cables/terminals are clean and tight, both ends. Starter bolts are tight.

Battery: Fully charged. 12.7 volts approximately. Cheap and quick load test the battery. Connect a voltmeter to the fully charged battery. Try to start the engine. The voltage on a good battery should not drop more than 1� volts during this test. If the battery voltage drops to 11 volts or lower consider replacing the battery. You can have the battery tested at any shop selling batteries. You could try jumping the battery from a running vehicle to see what happens.

The only thing left is the starter.

Thanks again!!!

Thanks!!!