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Discussion Starter #1
Does anyone know what the cause of, the entire Right Front Headlight Assembly Not Functioning, might be?

I have replaced the Right High & Low beam fuses and it fixed the problem for a few days. I checked the replacement fuses and they all seem to be fine. Granted 1 was missing a 10A and used a 15A to get me by for a little while.

Should I test the voltage at the BMC and at the Lamp?

Not sure where to start.... Blinkers wont work and thats no good. I see a ticket in my horizon.

---------- Post added at 04:10 AM ---------- Previous post was at 02:21 AM ----------

So I came across this.....

I will replace ALL these and hope for the best that it is actually NOT the PCB Board that has broken.

Printed Circuit Board (PCB) Relays - Not Serviceable
DRL PCB Relay



DRL Fuse
FOG LAMP PCB Relay
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FOG LAMP Fuse
HI BEAM PCB Relay
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LT HI BEAM Fuse, RT HI BEAM Fuse
HORN PCB Relay
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HORN Fuse
LO BEAM PCB Relay
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LTH LO BEAM Fuse, RT LO BEAM Fuse
PRK LAMP PCB Relay
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PRK LAMP Fuse
TRUNK PCB Relay
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Rear Compartment Lid Release Actuator
 

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I had the same issue. I replace the bulb only to discover it didn't work. I just tried the fuse (an hour ago) and it fixed it.
Hopefully it keeps working.

What ended up happening for you? Did you end up needing to replace anything other than a fuse?
 

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Discussion Starter #3
Well, I just replaced each of the PCB fuses. Did not solve the issue. Going to take the multimeter and test the voltage at the lamp connector. From my reading, if there is no voltage from the positives then there is a or some bad solinoids. Which I think means a complete fuse box replacement...

Coby7 can you confirm this?
 

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Good one coby, your headlights are running in a parallel circuit, if you understand circuit operation, if one headlamp is completely out..here is something cool to do and works...first, take out your headlamp relay that is not working, should be either RH or LH, look at the relay to find (should be a standard 4 point BOSCH type) where the connector runs to make a straight line. Take a wire (18 gauge single wire like from a speaker). Tap each end where it shows where the connection would draw a straight line, if headlight turns on with the lights set to on, then your relay is faulty and fuse is good. If not, then either you have high resistance on either connection or its an open in the circuit.
 

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Discussion Starter #6
Thanks Coby and 5t!

Not knowing. Where can I locate each the RH and LH relays? I know the fuses are in the box.

I'm driving a late model 06 SS/sc. With many 07 parts, like the radio and antenna.
 

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if your able to remove the relay where the battery junction box (under the plastic battery picture with a positive connector on the driver side dash), underneath that will be all of your PCM controls and junction box. Look on the reverse removable plastic top and look for RH or LH depending on which one is out. Dunno if it applies to the 05-07 models, but seen it on my 09.
 

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5t3alth

Relays are non serviceable on a Cobalt, they are part of the fuseblock.
 

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Discussion Starter #9
5t3alth

Relays are non serviceable on a Cobalt, they are part of the fuseblock.
So hypothetically speaking, since I have not had a chance to block test yet....

if the RF relay is broken, is there a temporary solution to work out? I know I am inching closer to a Fine.

Like... "Tap the Positive and Control (if there) Voltage/Ground From the right, minus the turn signal, and run to the right side of the vehicle? For Turn Signal, Tap the Rear Right?
 

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If none of the bulbs work you lost the ground. It either broke, burnt,corroded or simply disconnected. Only thing common to all.
 

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Discussion Starter #11
Well that's actually great news. That sounds solvable.

If my logic is correct all I would have to do is take some matched gauge wire. Attach it to the plug at the lamps, run it through the bay to the (underside of the 2nd level on the fuse box and re-solder appropriately?
 

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Or just find the problem...
 

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5t3alth

Relays are non serviceable on a Cobalt, they are part of the fuseblock.
Oh wow, I learned something new, so GM is thinking like Nissan and in order to replace a permanent relay, you would have to replace the whole junction box, wow, we at Nissan call them the IPDM E/R which is a module with permanent relays attached with fuses.

It can be a ground since headlights operate in a parallel circuit. If you have an open in the circuit, it wont complete the circuit and will not operate. Its either power, ground, or signal wire then :)
 

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Discussion Starter #14
If none of the bulbs work you lost the ground. It either broke, burnt,corroded or simply disconnected. Only thing common to all.
DING DING DING!

As usual, luckily for us all, you are correct. The ground is loose at the connection to the headlamp assembly. Right now I just have tape holding the wire in tight.

Anyone know if a good DIY on how to fix the connection points? I haven't the slightest idea.
 

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Maybe the pin just pulled out a bit in the connector . Disconnect and check for a pushed pin.
 

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Gotta love them pigtails for backprobing :)
 

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This is what happened to mine. Notice pin on the right is pushed in. This was two years ago, I took a picture for future reference.


---------- Post added at 09:03 PM ---------- Previous post was at 09:01 PM ----------

I just pulled it back into place.

---------- Post added at 09:04 PM ---------- Previous post was at 09:03 PM ----------

 
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