Boat › Basic electrical › Bad electrical connection

Bad electrical connections can cause many different problems. A broken or disconnected wire will stop electricity flowing completely, but it is also possible to have a bad connection that causes high resistance.

How bad a corroded connection is

These twisted, corroded wires measured about 250,000 ohms across the joint, so almost no voltage made it through. After cleaning them and joining them with a solder sleeve, the same joint measured 0.1 ohms (at 28:19). That's the difference between a bilge pump that works and one that doesn't.

PHOTO Dangar Marine

How to diagnose an electrical connection

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A corroded connection can take most of the battery voltage, leaving a globe or device with almost nothing. I show how to find it with a multimeter voltage drop test, then clean or remake it.

How to make a good electrical connection

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It is much easier to make a good electrical connection in the first place than to find and repair a bad connection when it eventually fails. This topic talks about some best practices for electrical connections.