I cant get the hood light to work so i went to the local chevy store and ordered a gm underhood light, I plugged it up and NO LIGHT, i tested with a multimeter any where you toch it the meter is reading 12volts but the light dont come on, even when you touch the top and bottom of the actual light bulb it is rerading 12v but no light, what is my problem???? HELP

 

Check to make sure you have a good, non-corroded ground.

 

Put your meter on ohms and see if there is continuity across the bulb. The filament might be broken.

Also you know if the hood is open more than 10 minutes the BCM turns off the light. The BCM usually uses the ground to turn things on and off. Try closing the hood and re-opening it.

 

where does it ground to, the light bracket is just rivited to the hood. Thanks for then reply

 

the bulb is fine if you take the bulb out and touch it to the battery it comes on

 

Two wires, one + and one -

 

If I unplug the connector from the light bracket and put my meter on the connector it works fine , but not when you plug to the light on the hood, This is very strange to me.

 

There is a switch inside the part that is riveted to the hood that is sensitive to whether the hood is up or down that turns off the light when the hood is closed. It's bad.

 

so How do I change that , or just take the bulb out and forget it? lol, Thanks for all the help

 

Hmmm...I would think if he has 12 volts to the socket, it wouldn't be the switch.

 

I am completely baffled, looks like if i had 12volts it would work but it isnt, Very weird, unless I am missing something, I would pull my hair out but It is shaven off, LOL

 

I am going to scream, so here is to all that is trying to help

 

The underhood light is controlled by a load sensing micro relay(#43),which is in turn,controlled by the BCM.
This little arrangement is a lot more complicated than you'd think-if the load isn't adequate,the light will come on very dimly,or not at all.
Or,if the relay is bad,it won't notify the BCM that it needs power,and the BCM won't ground the relay to turn the light on,and begin the countdown(monitored) to when it turns the power off.

It sounds to me like you may have a bad microrelay.

The only reason I know anything at all about this is from installing an led underhood light,which would only illuminate dimly until I wired a tiny incandescent bulb into the circuit,then the relay would sense adequate load,and tell the BCM to ground the microrelay,which turns the power on,and everything was fine.

I'm not sure how this is going to help the OP,except to point out that there's a lot more to that little light than meets the eye...

 

/Any other ideas on my light?

 

When you get 12 volts on your meter, are you going from the light connector sockets to a ground somewhere else on the car (not on the connector socket) ?

If so, something is probably wrong with your BCM/relay. As was said there is always 12 volts at the socket, the BCM grounds the circuit to turn on the light.

 

If its's the bulb holder that's bad you could try posting in the parts for sale section and see if anyone who has changed out there hood and not reattached the lamp has one lying around. Unfortunately I didn't plan on reattaching it and left mine off when I swapped out my hood with the body shop, otherwise I would have given it to you.

 

Yeah I am grounding from the. Battery . Where is the bcm relay I need to change?

 

I bought a whole new light and still nothing.

 

LOL...I never did get mine working...To be honest, I gave up but didn't even put in the effort you've gone to already...

 

Carcass says it is micro relay #43, it is located:

Instrument Panel Fuse Block
The instrument panel fuse block is located on the passenger’s side of the vehicle, under the instrument panel and under the toe-board. Remove the carpet and toe-board covering to access the fuse block by lifting up on the latches at the top of each corner of the panel. Then turn the fuse block door **** counterclockwise and pull the door to access the fuses.

Minifuse Usage
1 Console Cigarette Lighter
2 Monitored (Inadvertent) Load Control
3 Lumbar Seat
4 Driver Seat Control Module
5 Radio, Compact Disc Player
6 Parking Lamps, Taillamps
7 Cigarette Lighter
8 Stoplamp, Hazard Flashers
9 Body Control Module
10 Windshield Wiper/Washer
11 Accessory Power
12 Blank
13 Body Control Module - Ignition 1
14 Crank
15 Hazard/Turn Signal
16 Air Bag
17 Tonneau Release
18 HVAC Controls
19 Instrument Panel Control
20 Cruise Control
21 Automatic Transmission Shift Lock Control System and Inside Rearview Mirror
22 Body Control Module - Ignition 3
23 Body Control Module - Ignition 2
24 Radio Antenna
25 Body Control Module - Ignition 1,


Instrument Panel Control
26 Hatch/Trunk Release
27 HVAC Controls
28 Bose Speakers
29 Diagnostic
30 Right Door Control Module
31 Power Feed Door Right
32 Fuel Tank Door
33 Door Control Module Left
34 Power Feed Door Left

Circuit Breaker Usage
35 Driver Power Seat
36 Passenger Power Seat

Micro Relay Usage
37 Monitored (Inadvertent) Load Control
38 Right Daytime Running Lamp
39 Hatch/Trunk Release
40 Left Daytime Running Lamp
41 Tonneau Release
42 Courtesy Lamps
43 Automatic Lamp Control Parking Lamps
44 Automatic Lamp Control Headlamps

Mini Relay Usage
45 Bose Speakers
46 Rear Defogger

Maxifuse Usage
47 Ignition 1
48 Rear Defogger
49 Blank
50 Ignition 2
51 Blower Motor
52 Starter
53 Blank
54 Headlamps