Mercruiser J1171 Trim Pump problem.

[mjrhoads]

'98 Mercruiser Alpha I (Gen II?) J1171 trim pump quit working - looking for troubleshooting advise!<br /><br />There are two relays with two lugs that control the pump. The top relay lugs connect to the Blue wire of the pump, and the other connects to +12V. The bottom relay lugs connect to the Green wire of the pump, and the other connects to +12V.<br /><br />When I press the trim button on the throttle control (either down or up), the relays will click, but the pump motor does nothing. If I measure the voltage on the pump wire leads (blue or green wire), they BOTH have either 0 volts (when the trim button is not pressed) or 12 volts (while the switch is in the up OR down position).<br /><br />I thought that only one of the wires would have 12 volts on it at a time (for example, +12V on green, 0 volts on blue for up - and the opposite for down).....why would they both have 12 volts?<br /><br />Any other ideas to check?

 

[bjenkinsnc]

Re: Mercruiser J1171 Trim Pump problem.

Your readings seem normal as the high resistance of the meter is completing the circuit to the other side of the motor. You will only have one path for current to flow, and that will be thru the solenoid that is energized. <br />You could rig up a switch capable of high current, go from fused power to one side of the motor at a time and momentarily turn the switch on, then immediately off. Motor should attempt to start in direction tested. Always make connections with NO POWER, then try, as you want NO SPARKS near motor. If not comfortable with this, have it done professionally.<br />I'm only an experienced electrical troubleshooter, not a guru...

 

[bjenkinsnc]

Re: Mercruiser J1171 Trim Pump problem.

Another thought..Check the gounding of the third lead from motor.

 

[bjenkinsnc]

Re: Mercruiser J1171 Trim Pump problem.

Possibly a correction to my first reply..Readings would be as expected only IF ground wire is OFF. Check the ground.