Some electrical 101
PH,
welcome to the forum.Ā I am a fellow 6CTA owner.Ā I had our mechanic remove the fuse that operates that activation circuit for the heater grids one our engines.Ā If someone just disconnected the wire from the grid connection then there is power on that set of connectors,Ā that is not an ideal situation to have power on those just dangling.Ā As to your question, a basic Fluke 107(or other brand/model) Digital Multi Meter is what I would consider to be a mandatory item in any tool kit on a boat.Ā You can measure both AC and DC voltage, resistance, current and other handy things.Ā You can simply attach the leads of the MultiMeter to the connections to the grid.Ā The one that is attached to the grid and the dangling wire.Ā When you go to start the engines the grid should activate and you should see 12 or more volts across those connections.Ā since it is DC you will see a negative number if the leads are connected backwards.Ā Thus you will be able to know if that is the + or – wire that is dangling based on the reading.
Those grid heaters draw significant current and are an extra draw on your power source at start up.Ā If the grids are connected, and the engine is running you can watch your volt meter on the dash and see the fluctuations as the grid cycles on and off.Ā When my wife and I first bought our boat we saw that voltage fluctuation and had our mechanic remove the activation circuit fuse as opposed to disconnecting one of the wires.Ā He was doing some other work so we had him do it while he was down in there otherwise I would have done it myself.
You can use other methods of warming your engines than the grid heater.Ā Wolverine makes a 250watt oil pan heater, appropriate for the 6CTA and SBMAR sells, that heats the entire engine in a much softer method so that you will see a decrease in black and white smoke at startup.Ā Also those Wolverines run on AC power while you are at the dock.
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