The Mariah Owners Club - up trim inop

Hi twospeed46,

From my experience with the Alpha 1s on my old SeaRay and other friends boats, most of the time it was a bad up trim limit sensor on the gimbal or its wiring was corroded and not the switch or solenoid. A bad trim sensor prevents the up trim function but not the up trailer function because the up trailer switch bypasses the trim sensor. First, check the connectors for signs of corrosion and clean as needed then test again.

Here's a way to check if the sensor, switch or the trim pump solenoid or wiring is bad:
1) Lower your outdrive as low as you can get it. (must be below the up trim limit)
2) Locate the trim sensor wiring on the inside of the transom. (Both trim sensor wires should be black, one should have a blue identifier and be plugged into a connector with two blue/white wires and the other trim wire will have a purple identifier and it will be plugged into a connector with a single purple/white wire)
3) Disconnect both wires, take a DVM, stick each probe into one of the black wires and check the continuity of the sensor. (a good sensor will read as a short, a bad one will read as open with the outdrive down)

If the sensor checks out OK, do the following:
1) Check the battery for 12 volts (fully charged)
2) Take the previously mentioned connector with the purple/white wire and stick the DVM's positive probe into it and ground the Negative probe
3) Press the up trim switch and see if you get 12 volts. If you do, then the up solenoid or the wiring to it is bad and if you don’t get anything or a much lower voltage, then it would seem that the switch or its wiring is bad so try cleaning the switch and checking any connections in the wiring.

A final way to check the up solenoid or its wiring:
1) Take a piece of wire connected to the positive side of the battery and briefly touch it to the up solenoid terminal that the blue/white wire is connected to. (this bypasses the up trim switch, the up trim sensor and the up solenoid wiring). If the pump runs, the wiring is faulty and if the pump doesn't run, the up solenoid is bad.

Good luck,
WetWilly