New Holland Tz25da won't start

[SuperBeetle]

Checked all safety switches...all ohm properly. Headlights work. When ignition switch is turned on glow plug light do not illuminate and starter does.not engage. Battery fully charged. Fuses all check out good. What am I missing? Nearest repair shop is 75 miles...and they start charging on their way to diagnose the tractor..this does not include parts and labor... attempting to avoid this out of pocket cost.

 

[3 Horse Ranch]

I have had that problem, on mine it was a connection going to a safety switch that got corroded. Cleaned it up and it starts fine. Mine is an older Ford New Holland 27 hp. simple but generally reliable. Check all of your connectors, unplug, clean and try to start, if no joy go to the next one.

 

[barbqranch]

If you can get someone to help you, measure the voltage between the big stud on the starter, and a nearby ground. Have the other person try to start. If the voltage doesn't go down, check the voltage at the small stud where the solenoid gets its current to close. If it gets voltage to close but doesn't, then I would assume it is a bad solenoid. If the main voltage drops way down when you try to start it, there is most likely a bad cable/connection (a common problem). If the small stud doesn't respond to the key, then you need to work that back.

 

[tmeric7]

If your electrical circuit is similar to mine (TC29DA), I'm really curious about the glow plug lamp light because I think that should conme on when you turn to ignition and that is separate from all the safety checks. If you have an operators manual, can you attach a pic of your starter system circuit diagram with the glow plugs? I would check on current to the glow plugs with a multimeter: + to glow plug bussbar, and - to ground. You're looking for around 10V when switched to ignition (on a timer) or while trying to start. Are you sure you have a strong battery?