How does the Engine bay light work?
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Junior User
Joined: Aug 2011
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From: Oakland, CA
How does the Engine bay light work?
I just put in a new bulb in the engine bay light socket (my truck didn't have a bulb in the socket). After jiggling the cable a bit I got it to turn on with the truck off (no lights, no keys in ignition). I partially closed the hood and can see the light turn off just before it shuts closed. How does it do that? I traced the cable back to the terminal and there doesn't seem to be a switch like on the doors. Am I missing something?
Posting Guru
Joined: May 2010
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From: Alton, MO
It is a mercury switch. When you open the hood it runs to one end completing the circuit (well it triggers the connection). Hood down and the mercury moves to center making it not heavy enough over the contacts to maintain connection. It is built into where you put the bulb (usually).
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Junior User
Joined: Aug 2011
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From: Oakland, CA
Get out of here! Really? I've never heard of that. I wonder if it's prone to failure in older trucks. i.e. turning on at night and therefore drains the battery. Maybe that's why there was no bulb in there...do you have a bulb in yours?
Posting Guru
Joined: May 2010
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From: Alton, MO
I don't have anything under my hood. Came that way when I bought it and doesn't really matter to me. I do have an operational underhood light in my '90. As to going out on older trucks. Let's think about that for a minute. Truck is 40 years old. Assuming switch is original to the truck I would assume it gong bad to be highly likely. After all it is 40 years old. They are cheap.
Fleet Owner
Joined: Dec 2009
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From: NorCal
90s F-Series and Broncos have under hood lights... cheap from the JY and a nice lil detail. Get two of 'em, one for each side of the engine bay. Additional sets are good for footwell lights.. I'm not a fan of the single dome lights.
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Junior User
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From: Oakland, CA
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Fleet Owner
Joined: Jun 1999
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From: Creedmoor, North Carolina
HIO, Not sure about 2 of them, the one in my 86 has like a 25 ft. cord on it. The light can be pulled to the rear of the truck.
John
John
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Fleet Owner
Joined: Dec 2009
Posts: 20,678
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From: NorCal
Is that 25-foot cord a factory part? I gotta look for one if it is!
As a matter of convenience, it can be a PITA cuz sometimes ya just wanna pull in and get out. Personally, my driveway is nearly 18 percent slope and I hate backing up a hill.
Posting Guru
Joined: May 2010
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From: Alton, MO
I had a truck with all the wire as well. The end of the light assembly turned 1/4 turn or so and the end came out with a "cord" so you could move it around. These are usually big plastic lights. Mine was also in a F series truck but don't remember what year.
Fleet Owner
Joined: Jun 1999
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From: Creedmoor, North Carolina
John
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