Weird Under Hood Light Problem
Thread Starter
Pro
Joined: Mar 2008
Posts: 552
Likes: 2
From: Dubuque Iowa
LoL... I may need professional assistance on this problem, I'm starting to feel a little dumb!
You would think with the way that diagram reads that other lights would also not be functioning, unless there is a problem at the junction of the underhoodlights and everything else. That is the last thing I can come up with to check!
You would think with the way that diagram reads that other lights would also not be functioning, unless there is a problem at the junction of the underhoodlights and everything else. That is the last thing I can come up with to check!
Thread Starter
Pro
Joined: Mar 2008
Posts: 552
Likes: 2
From: Dubuque Iowa
Thread Starter
Pro
Joined: Mar 2008
Posts: 552
Likes: 2
From: Dubuque Iowa
Those are connectors....I'm not sure....the diagram doesn't show that if it does...I have my underhood lights disconnected (the plugs by the headlights)because those lights will kill your battery quick if the stay on from a stuck/failed /failing mercury switch...most people I know unplug them for the same reason.
But my mercury switches are newer so I am not so concerned with them yet.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Ok here is a snapshot of the diagram.....aint nothin' to it. Just 2 connectors, the head/parking switch, mercury switch and the lamp. You can troubleshoot it all day.....but turn the headlights or parking lights on and see if you get power back at the bulb socket first.
The underhood lights get their power from the CTSY/CLK fuse and not the headlamp switch. If you trace the circuit back from the light, it shows that power to the entire circuit is only there with the headlamp switch in an ON position. The underhood lamps are supposed to work anyime the hood is up.
The circuit number shown in this example diagram is "9" and in my book, it's "40" The wire color above says Brown, and in my book the real wire color Orange. Also, the 2-wire harness from the connectors to the lights themselves are both black. Only the part of the harness that lead to the connectors has an orange and black wire.
The "crescent-shaped" figure indicates a wire connector. The ( side is the female connector and the sort of backwards D is the male side. The number is a reference number for using the FSM Component Locator Table.
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Pro
Joined: Mar 2008
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From: Dubuque Iowa
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Thread Starter
Pro
Joined: Mar 2008
Posts: 552
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From: Dubuque Iowa
No luck, I spent an hour yesterday trying to follow the lines but its pretty hard to get into some of those tight spots and get into the black harness... I eventually gave up because there were too many wires haha. I figure it is not a ground because every other accessory works, and works well! The thing that puzzles me is that I had power to the underhood lights before I installed the bulbs and as soon as I had the one flash, I had no more power to them.
The only thing I can come up with, is there must be an inline fuse somewhere just for these lights. I am out of ideas after that.
My other option is I am going to splice the underhood light wires to the side front ambers. That way the underhood lights will only come on when I pull the headlamp switch out one click, and when the hood is closed and I turn on the headlamps the underhood lights will remain off because of the mercury switches.
Anyone think I will have a problem with blowing a fuse if I do that?
The only thing I can come up with, is there must be an inline fuse somewhere just for these lights. I am out of ideas after that.
My other option is I am going to splice the underhood light wires to the side front ambers. That way the underhood lights will only come on when I pull the headlamp switch out one click, and when the hood is closed and I turn on the headlamps the underhood lights will remain off because of the mercury switches.
Anyone think I will have a problem with blowing a fuse if I do that?
Team Owner
Joined: Dec 1999
Posts: 34,873
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
If you are going to provide a different power source, why not use a 12v source that is always hot? You can run a power wire from the so-called "jump-start" post that is behind the battery and where the fusible links are.
Use 18 gauge wire and put a 5A fuse and a small toggle switch on the hot side of a new line and you have lights that will still stay off with the hood closed. When you open the hood for long periods, use the toggle switch to turn them off.
Use 18 gauge wire and put a 5A fuse and a small toggle switch on the hot side of a new line and you have lights that will still stay off with the hood closed. When you open the hood for long periods, use the toggle switch to turn them off.
2nd Gear
Joined: Dec 2008
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...I have my underhood lights disconnected (the plugs by the headlights)because those lights will kill your battery quick if the stay on from a stuck/failed /failing mercury switch...most people I know unplug them for the same reason
I also have mine disconnected due to failure of mercury switch and resulting dead battery.
Where can we find new mercury switches ???
I also have mine disconnected due to failure of mercury switch and resulting dead battery.
Where can we find new mercury switches ???
Advanced
Joined: Jul 2008
Posts: 51
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From: Shelton Connecticut
Most auto supply stores should have them. If not, online parts suppliers have them i.e.
Ecklers:for $10.99 + shipping http://www.ecklers.com/search.asp?ac...searchHistory=
Zip for 10.95 + shipping http://www.zip-products.com/Zip/prod...1E5EE2BA963184
Ecklers:for $10.99 + shipping http://www.ecklers.com/search.asp?ac...searchHistory=
Zip for 10.95 + shipping http://www.zip-products.com/Zip/prod...1E5EE2BA963184
Racer
Joined: Aug 2008
Posts: 326
Likes: 5
From: central Florida Florida
I drilled a hole in the square tubes that the wires run along under the hood and installed some black rocker switches to turn the hood lights off if I have the hood up for long periods of time.
Pro
Joined: Mar 2007
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From: Mt Prospect IL
2025 C4 of the Year Finalist - Unmodified
Check by the vacuum canister by the left front turn signal in that well area. Both lights merge and there is a small plug that houses a fuse. That fuse is additional protection for the underhood lights. Make sure it didn't blow.
Thread Starter
Pro
Joined: Mar 2008
Posts: 552
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From: Dubuque Iowa
I don't have my vette with me as I am back at school and there is snow here, but I graduate a week from today and will have to look it over again then. It may be different than yours tho, it is an 87. I guess I'm not sure.
