FOOL GAUGE

Q:

My fuel gauge stopped working. What should I check first?

Ed Harrow San Diego

A:

First, check that the wires are connected, then make sure they are not corroded at the connection to the gauge. Next, a multimeter, set to ohms, can be used to determine if the wire is broken (called a continuity check). If all that checks out, go to the fuel-sending unit on the

fuel tank. Place a jumper wire from the center positive terminal to the ground tab on the side of the sender. Your fuel gauge should pin to full. If it does not, then you have a bad fuel sender. Replace it. Directions for replacing a fuel sender can be found online at boatingmag.com/story/how-to/ troubleshoot-your-boats-fuel-gauge.

ONE HOT, ONE COLD

Q: Hi Doc. I have a twin inboard cruiser. One engine runs at 165 and the other at 190. This never changes, and both engines seem fine. Should I be worried?

Van Smith Montgomery, Alabama

A: Without knowing the make and model, it’s hard to be too specific. But to get started, try these things. First, swap the leads on the temperature gauges to rule out a problem with the gauges or sending units. Also, is a thermostat rated at the same temperature installed in both engines? Does the coolingwater discharge at the exhaust appear to be similar in volume? If not, were both pumps serviced at the same time? I’d want to know why a 25-degree temperature difference was occurring, even if my engines appeared to be running fine.

Good luck.