A scratchpad post as I diagnose and repair an electrical fault in our Power Trac PT-1850. Pretty sparse right now, just starting.
- Reset circuit breaker
- Turn ignition on without starting motor — I get the normal beeps, flashing strobe and 12.4 volts on the gauge (normal for a 12 volt battery at rest)
- Crank and start the motor
- Voltage drops to around 11 volts (indicating to me that something is really pulling hard, maybe a short) and stays there for about 15 to 30 seconds, then the breaker pops and the voltage jumps up to 13.2 (pretty normal alternator-charging voltage, battery seems to be getting charged up).
- With the breaker open/popped the strobe stops flashing. But tilt seat, emergency seat switch and draft control are still operational and the tractor made it back to the barn (about a mile).
- Use the ignition switch to shut off the engine (which is weird because the breaker is right in front of the ignition switch in the wiring diagram, so why does it still work?)
- The ignition switch is dead *after* I shut the engine off — no strobe, no beeps, no voltage on the gauge when I key it on.
- Return to number 1 above
My current theory is that I have a short (first project — see if I can figure out which circuit it’s in, and where). One option is to replace the alternator (I have one coming, but at $600 I’d like to avoid opening the box if I can).
Here’s a PDF I got from Power Trac (which is newer than my machine and doesn’t match up as the next one – figuring out which one is right is another task for today)
Here’s an older GIF (I need to retrace my steps to figure out where I found this on the ‘net)
Here’s a pretty good example of how a lot of Power Trac puzzlers get solved by the gang on TractorByNet. This long thread talked all around the issue, which was eventually solved by replacing the alternator. Here’s a link to that thread.
But in addition I a) bought a second PT-1850 so that time-critical projects could continue during breakdown times and b) sent this guy back to PowerTrac for repair plus an 800-hour