Relay 12 v drops to 3 volts

2011 HYUNDAI I20
43,900 MILES • 1.1L • 4 CYL • 4WD
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L TIATOM
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  • 61 POSTS
With key at "on" position, 86 of the C/Fan Relay has 12 volt, and 85 had 1 volt respectively. This relay sits on the engine compartment box.

Now, my issue is that as a test light bulb with its one end connected to 86 and other end to ground, the bulb did not glow. Same case for testing a relay. In both cases, the voltage across each loads is about 3 volt. Why is this happening?
Apr 7, 2020 at 8:11 PM
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STEVE W.
  • ✓ASE Certified Mechanic
  • 15,200 POSTS
  • ASE Certified Mechanic
Loss of voltage when testing under a load is 99 percent of the time a bad connection, either corrosion or broken wires. It's also possible the relay is internally shorted, but that isn't really common, usually they fail open or the coil burns out. Your description sounds like corrosion, It's got enough connection to read on a voltmeter, but as soon as any load is placed on it, the voltage drops because of the poor connection.
Apr 7, 2020 at 9:22 PM
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