Not getting 12V at the underwood light socket
Thread Starter
Melting Slicks
Joined: Aug 2014
Posts: 2,470
Likes: 460
From: East Windsor NJ
Not getting 12V at the underwood light socket
Installed a new underwood LED light and was barely getting any output from it. Measured the voltage at the socket with my meter and only 0.5. Checked fuse #2 in the foot well and surprisingly found it was “partially blown” - evidently conducting some electricity, but not all. I installed a new fuse and now I’m getting more voltage but still only 7.5. Any thoughts why I am not getting 12 - or is 7.5 what’s supposed to be there?
Thread Starter
Melting Slicks
Joined: Aug 2014
Posts: 2,470
Likes: 460
From: East Windsor NJ
Lesson learned - better off to install the underhood light THEN install the fuse. It is very easy to blow that guy. I don’t know what size fuse is supposed to be in there - but went from a 10 to a 15 and things seem to be working OK now…..
Instructor
Joined: Jun 2025
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You want to see voltage that the same as the battery voltage.
If it’s not, you have a problem. First step: Take your multi meter, disconnect the positive off the battery, measure your hot wire terminal on the light to ground away from the light for continuity, to check for a shorted hot wire.
Last edited by Gorn Captain; May 29, 2026 at 08:49 AM.
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Melting Slicks
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From: NJ
First off, the LED light draws a minimal amount of current, putting a larger fuse in can cause a fire. Fuses are there to protect the wire, not the device. Sounds like you have a frayed wire somewhere most likely the Pos. wire. Did you check the voltage between the Pos. at the socket and the Neg. at the battery or Neg. at the socket? A difference (say at least 2 Volts) in voltage between checking the socket (Neg) and Socket (Pos.) and checking the Batt. Neg. and socket (Pos) would indicate a bad ground. And the fuse size should be shown on the fuse panel directory or on the actual fuse block.
Melting Slicks
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From: NJ
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Melting Slicks
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From: Horseshoe Bend ID
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Strange then why Corvette specific light & accessory suppliers list LEDs for the hood light.
https://www.vette-lights.com/products/1997-2013-c5-c6-corvette-under-hood-underhood-led-no-modification-to-housing
Mercury switches will make no difference to any load they supply. It’s just Liquid Metal in a glass capsule that moves to one end where there’s two contacts, thereby closing the circuit.
https://www.vette-lights.com/products/1997-2013-c5-c6-corvette-under-hood-underhood-led-no-modification-to-housing
Mercury switches will make no difference to any load they supply. It’s just Liquid Metal in a glass capsule that moves to one end where there’s two contacts, thereby closing the circuit.
Last edited by Gorn Captain; May 30, 2026 at 12:36 PM.
Melting Slicks
Joined: Mar 2004
Posts: 2,412
Likes: 414
From: Horseshoe Bend ID
Strange then why Corvette specific light & accessory suppliers list LEDs for the hood light.
https://www.vette-lights.com/product...ion-to-housing
Mercury switches will make no difference to any load they supply. It’s just Liquid Metal in a glass capsule that moves to one end where there’s two contacts, thereby closing the circuit.
https://www.vette-lights.com/product...ion-to-housing
Mercury switches will make no difference to any load they supply. It’s just Liquid Metal in a glass capsule that moves to one end where there’s two contacts, thereby closing the circuit.
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Joined: Jan 2007
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From: Dyer, IN
The underhood light circuit is controlled/monitored by the BCM and will shut it off after 15 minutes.