Drive trim sender - any way to test?
 

Bravo 1 XR, Short Sportmaster lower. Center drive trim reading on SmartCraft stays on 0.0 no matter what position the drive is in. Thought maybe the link rod or actuator arm was loose, so checked that and that wasn't it. I'm trying to rule out possible other electrical connections being the problem. Is there any way to test the sender itself ?

The three wire senders cannot be easily checked by measuring the resistance with a Ohm meter. Locate where the sender connects to the boats wiring harness, which will be near the transom, You will see a three wire Delphi connector with a red, white & blue wire leading to the sender. With the sender connected to the boat and the ignition ON you should see 5 volts on the red wire and ground on the blue wire. The voltage of the white wire should vary from 0.05 to 4.5 based on the position of the drive.

You should also confirm that the sender is properly indexed. Move the drives to the full down position and the remove the sender. With a volt meter on the white wire slowly rotate the sender to see if the voltage changes. The senders do not have windings a full 360 degrees so you need to rotate the sender so that the voltage reads between 0.500 and 1.00 volts with the drives full down. If you can rotate the sender one full turn and the voltage reading doesn't change then the sender is bad.

GF?

thanks. very helpful!