Rebel_Heart

My port engine oil guage is not working most of the time. The sending units on both engines were replaced. The guage didn't work today until I did a WOT run and then the guage read about the same as the starboard side. Shortly thereafter, it dropped back to not reading again. Any ideas?

Too Old

Start by swapping sending units from engine to engine. If theres no change, you've eliminated the posibility of a bad sending unit.

Outdrive1

You could also turn your ignition on and ground the wire at your sending unit. If the gauge moves all the way over then the gauge is fine and your sending unit is bad. If the gauge doesn't move then you either have a short somewhere in between, a wiring problem at the gauge, or a bad gauge. If you suspect the gauge then test for positive and ground. If you have both of those then ground the signal wire at the gauge. Once again if it moves, then your wire is bad in between, if it still doesn't move replace the gauge. It would probably be easier to run a new wire than to trace down a short.

Wobble

most oil temp senders are single wire, so check for contiuity from sender body to engine, might not be making ground, test guage as BAD K suggested.

nocigarette

throw those electrical gauges in the garbage and go with mech, at least due the important one oil press engine temp etc. i have had all kinds of problems with electric gauges.....to much money in the back of the boat to risk it..........