Another low beam headlight issue. Please help.

**Nicksmith5553** · 12-19-2016

So I just bought a 2007 grand prix gt about a month ago. So last week the low beams just quit working. I've replaced the relay,bulbs,and headlight switch. As far as I can tell I'm not getting power to the relay box. High beams work, all blinkers work. DRLs work. Fog lights even work. Checked all fuses and were good. Replaced all headlight fuses anyways. I'm stumped. Any suggestions on what to look for or where would be greatly appreciated.

**Fivefingerdeathpunch** · 12-19-2016

Did you replace the HDM module/relay?

That's a pretty common failure on the 04+ cars.

**Nicksmith5553** · 12-19-2016

Yep, first thing I did. Forgot to mention this. I pulled the headlights and found the brights to be spliced into the low beams so that they were forced to turn on when you toggle brights.

**stealthee** · 12-19-2016

Highs come on with lows from the factory on 04+. That is not your issue.

Check for power at the harness. I had a harness get hot once and it would intermittently lose contact. I replaced the harness and all was well.

**Nicksmith5553** · 12-19-2016

Well after I took the splice off the the two wires the low beams won't even light up with brights. Which harness? Do you have a link for one?

**stealthee** · 12-19-2016

The plug in that the bulbs themselves plug into.

**Nicksmith5553** · 12-19-2016

Even though they seem fine?

**stealthee** · 12-19-2016

Check for power there, then work backwards. Find out where you lose power at and go from there.

**Nicksmith5553** · 12-19-2016

I im not getting any power from the relay. And have changed the relay.

**stealthee** · 12-19-2016

Are you getting power to the relay? Are you sure you checked/changed the right relay?

**Nicksmith5553** · 12-20-2016

I'm 100% positive relay has been changed. I'm also positive the relay isn't getting power. #35 hdm module

**Jmoonfd** · 12-20-2016

So of relay isn't getting power where do we go from there ? I'm in the same situation also

**Nicksmith5553** · 12-20-2016

So I thought about hot wiring a dummy switch into both lights to limit power to the outside light. While splicing the high beam back to the low beam. So that I can keep high beams on, and use the two dummy switches to toggle the "actual brights" if that's making sense to anyone.

**Swiggles** · 12-20-2016

Could this be a bcm issue?

**Nicksmith5553** · 12-21-2016

How could I check? I've worked in a variety of cars and tbh this is the weirdest problem I've ever worked on lol luckily local law enforcement was nice the other day and let me go with a warning!

**stealthee** · 12-21-2016

For the time being you could actually put your high beam bulb in your low beam part of the headlight and just keep your headlights on high beam, but they will be "muted" due to the cover part of low beam lense. I did that when my HDM module crapped until I could get a new one.

**Nicksmith5553** · 12-21-2016

I'll definitely try that for the time being, thanks a bunch!

**Nicksmith5553** · 12-22-2016

So how to I get a new bcm? Should I just go to the dealership?

**nox** · 12-22-2016

Could it be the headlight switch itself in the column? No power to the relay, that would be where I start before the BCM.

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