1999 Dodge Caravan rear defogger problem

The relay is in a junction box(block) in the left side interior, behind dash. It's protection is under the hood, fuse 27, 40 amp. There are protections in the interior fuse block also. Fuses 9, 6, and 12. 15amp, 20amp, and10amp. Ok

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I do think it best for you to use a meter, or 12/6 volt test light, but I'm sure you do. So many fuses are ok, and have no power to them. They make a kit, it is a type of paint, and it matches the grids on the defogger circuit, right on the glass. You tape up the areas you do not want to spread on, and repaint the circuit, just in case the grids go out. With 11.5 volts on the ground side I'm sure you will find the problem now.
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Fuses aren't the problem. How do you explain the voltage there? Voltage on the ground side, (both sides), indicates an open ground connection. If you have voltage on only one side, you have the supply and ground sides mixed up in your mind.

No voltage on either side: look at the fuses.

Voltage on both sides: open ground connection

Voltage on one side and 0 volts on the other: proper operation. Every grid line should have around 6 volts in the middle. If 0 or 12 volts, slide the test light or meter along the line until you find where the voltage changes. That's where the break is. Follow ch112063's recommendations for the fix.

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