Minuteman ER26 Service Manual page 45

11. Identifying the Cause of Trio Failures
1. 1. Check for loose or burnt connections on the controller, batteries, cables and the circuit breaker. Check for loose or burnt connections on the controller, batteries, cables and the circuit breaker.
Make the sure the circuit breaker is not damaged (burnt or cracked). Make the sure the circuit breaker is not damaged (burnt or cracked).
2. 2. Test the chassis drive motor harness for broken wires. Disconnect the plug, labeled 'Traction" on Test the chassis drive motor harness for broken wires. Disconnect the plug, labeled 'Traction" on
the Trio controller. Connect a digital multi-meter to the plug on the two large wires. Set the meter the Trio controller. Connect a digital multi-meter to the plug on the two large wires. Set the meter
for Ohms (resistance). The SCV2832 resistance on the 748010 chassis drive motor (This has a for Ohms (resistance). The SCV2832 resistance on the 748010 chassis drive motor (This has a
black wheel) should be .3 to .4 ohms. The ER2832 chassis drive motor #281400 (has red or dark black wheel) should be .3 to .4 ohms. The ER2832 chassis drive motor #281400 (has red or dark
blue wheel) should have resistance of 3.9 to 5.7 ohms. The Turn the steering wheel slowly in both blue wheel) should have resistance of 3.9 to 5.7 ohms. The Turn the steering wheel slowly in both
directions until it stops several times. Monitor the meter while turning. The resistance should not directions until it stops several times. Monitor the meter while turning. The resistance should not
change or vary while turning. Any variation even .1 ohm could be indicating a partially broken or change or vary while turning. Any variation even .1 ohm could be indicating a partially broken or
broken wire, which could cause spikes and surges. This could possibly damage the Trio broken wire, which could cause spikes and surges. This could possibly damage the Trio
controller. controller.
3. 3. Test the two small wires on the "Traction" harness that go the electric brake (E-Mag). The Test the two small wires on the "Traction" harness that go the electric brake (E-Mag). The
resistance should be 60 to 80 ohms. Turn the steering wheel in both directions until it stops resistance should be 60 to 80 ohms. Turn the steering wheel in both directions until it stops
several times. Monitor the meter while turning. The resistance should not change or vary while several times. Monitor the meter while turning. The resistance should not change or vary while
turning. Any variation even .1 ohm would be indicate a broken wire or poor connection. turning. Any variation even .1 ohm would be indicate a broken wire or poor connection.
4. 4. Measure the total battery voltage at the batteries and at the battery connections on the controller. Measure the total battery voltage at the batteries and at the battery connections on the controller.
They should be exactly the same. A 1/10 of a volt or more difference would indicate a problem in They should be exactly the same. A 1/10 of a volt or more difference would indicate a problem in
the connections. the connections.
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