1800 Diesel
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- 768
- 25
- 18
- Location
- Santa Rosa County, FL
I mentioned this in an earlier thread but it was unrelated to oil light problem so I'm starting a new thread in case someone else runs into the same problem.
This unit was received in back in February of 2013 and it took several months before I could get to the pre-start maintenance and fluids work. After completing the standard pre-start list (for fluids, batteries & basic readiness checks), I attempted a regular start-up sequence. When I first set the switch to the start position I could only hear the fuel pumps running. After a few attempts I would sometimes hear the starter attempt an engagement and maybe the engine would rotate a quarter-turn or so, but with most start attempts all I could hear is the fuel pumps.
To troubleshoot I checked for 24v getting down to the starter solenoid and indeed it was. Then tried "shorting" across the battery lug & the solenoid connection but no starter rotation followed. At this point I removed the starter, removed & disassembled the solenoid and opened up the starter commutator/brush end. Found the following issues:
1) Commutator area was partially melted (may not be salvageable)...
2) Brushes worn down 70% and one side had a broken brush spring so this side was not even touching the commutator.
3) The contact surfaces inside the solenoid were heavily pitted and corroded. Cleaned these up and reassembled.
Other than the above issues, everything else looked good. Can probably rebuild it and turn the commutator & it should work--once I locate a source for the brush spring. For the time being I robbed a good starter off my donor unit, but would still like to rebuild the original.
Lesson here--when you think you're hearing just the fuel pumps, always check the starting circuit lead connected to the starter solenoid. You might just have a bad starter. So far this is the first time I've run across this scenario on the [typically] well-maintained machinery from DOD, but goes to show there's always a first time....
Kevin
This unit was received in back in February of 2013 and it took several months before I could get to the pre-start maintenance and fluids work. After completing the standard pre-start list (for fluids, batteries & basic readiness checks), I attempted a regular start-up sequence. When I first set the switch to the start position I could only hear the fuel pumps running. After a few attempts I would sometimes hear the starter attempt an engagement and maybe the engine would rotate a quarter-turn or so, but with most start attempts all I could hear is the fuel pumps.
To troubleshoot I checked for 24v getting down to the starter solenoid and indeed it was. Then tried "shorting" across the battery lug & the solenoid connection but no starter rotation followed. At this point I removed the starter, removed & disassembled the solenoid and opened up the starter commutator/brush end. Found the following issues:
1) Commutator area was partially melted (may not be salvageable)...
2) Brushes worn down 70% and one side had a broken brush spring so this side was not even touching the commutator.
3) The contact surfaces inside the solenoid were heavily pitted and corroded. Cleaned these up and reassembled.
Other than the above issues, everything else looked good. Can probably rebuild it and turn the commutator & it should work--once I locate a source for the brush spring. For the time being I robbed a good starter off my donor unit, but would still like to rebuild the original.
Lesson here--when you think you're hearing just the fuel pumps, always check the starting circuit lead connected to the starter solenoid. You might just have a bad starter. So far this is the first time I've run across this scenario on the [typically] well-maintained machinery from DOD, but goes to show there's always a first time....
Kevin
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