Re: Trim Gage
If you have a multi meter and know how to use it, it's easy to trouble shoot a trim sender and gauge.<br /><br />First, easiest thing is to check the wiring at both the sender (on the outdrive) and at the gauge. Make sure the connections are clean and solid. Most of my gauge problems have been caused by loose, cooroded connections or bad ground somewhere. Good chance this will be the problem.<br /><br />You then check the sender and gauge (in either order)<br /><br />To check the sender itself: The sender is simply a variable resistance switch - going from high resistence (blocking current) to low (sending current) depending on position. Find out the spec for the sender (what ohms it should have in up and down position). If your owner's manual doesn't have that spec - go on the Teleflex web site. They have a chart somewhere in there with various makes and models of motors' trim senders listed. Their gauges are designed to work with OEM senders, that's why they have that info. I know mercruiser's listed.<br /><br />Use your multi meter to test the resistence from the sender in full up and down position. See if the resistence matches the spec - or is close. The main thing you're looking for is that "up" and "down" both match with the intended reading in terms of high or low resistence, and that the transition from up to down is smooth. If it seems to be working but does not exactly match the spec (for instance if it's supposed to be 0 and is 5, or is supposed to be 150 but is 140), don't call the sender "bad" until you check the gauge and wiring. These are "ballpark" specs in my limited experience.<br /><br />If the sender checks out, you then check the gauge itself. This is simple - you check it with full power (short gauge's sender terminal to ground) and no power (disconnect gauge). This will mimic the sender sending it high resistence (no power) and low resistence (full power). I can't tell you if your gauge should read "up" or "down" at full power (and vice versa) - the spec for the sender will tell you that.<br /><br />If all the connections, sender and gauge all look good, my next guess would be the wire(s) from the sender to the gauge. You could check continuity or just run new, temporary wires to see if that helps.<br /><br />Good luck
