Low beams randomly not working
 

First question: This is actually in regards to a Z06, but not sure if I should post here, or Z06 forum because it probably applies to C6's in general. Please move this to the correct forum if needed.

It's happened a couple times now where I am driving at night, stop the car for a minute (off), and then when I go to drive again, the headlights do not come on. I try the different settings (auto, on, etc..) to get the low beams on, but the only thing that I can get to work is the high beams.

When I park it, and go out the next day, they are working fine again.

Any ideas?

In the fuse box in the engine compartment there is a Mini-relay for the Low Beams (#47).

You could test it by swapping it with Mini-relay #45 (Wipers on/off).

The Parking Lights use a different relay but if they are failing along with the Low Beams, then the problem could be the stalk switch.

You said that the low beams work again the next day. This sounds suspiciously like the same problem that several of us have experienced: the low beams quit working after the engine warms up.

If your problem is heat-related, the culprit is probably the backplane of the fusebox itself. A broken trace in circuit 1970, deep inside the assembly, goes open-circuit as it heats up. In my case it was dangerous, because the lamps would suddenly quit while driving home at night!

But first rule out the light switch itself. Cover up the light sensor on the dash or just wait until it's dark and twist the low-beam switch from Auto to Off. If the DIC says "Headlights Suggested" then you know the computer is receiving the signal from the switch.

If the switch is okay, you can isolate the problem pretty quickly with a multimeter. I'd start at the relay. Is it getting the signal? If not, go backwards toward the computer. If so, it's either the relay itself, or between the relay and the headlamps.

If your problem turns out to be the backplane, I strongly encourage you to report it to the NHTSA, because this is starting to look like a trend.

I describe it in more detail here: http://forums.corvetteforum.com/1577560168-post17.html

Will check it out
 

Wow! great info. Yes, so far it's only happened after i've driven the car a bit, so sounds like this is probably the problem. Now just have to wait till it happens again to test these.

I have the same symptoms in my 2008 C6. Dealer wants $695 to replace the fuse box. Ouch! I will definitly report it to NHTSA as per TorqueTube's suggestion.

Cheers

I just started getting this problem too! Tonight I was driving then, poof no lights. High beams work, fogs work, etc. I let the car sit for a while and they work again and then poof gone.

has anyone found out more about this? I'm getting this now on my 05.

there is a TSB maybe a recall by now. the relays in the underhood fuse box over heat and folks complain that their lights shut off while driving.

i had the same problem bought a new complete under hood fuse box and fixed it.

Got my notice, but only issue I've had is replace ballast, replaced lenses and bulbs! ****...had it for 9+ freaking years now. Hate to give the car to the freaking idiots, I mean dealer mechanics.

Hi all,


I just last week received my recall notice for this issue. This is GM recall #13146. It looks like the fix is a new jumper wire. This is what GM says the problem is. When your vehicle's engine is warm, the underhood bussed electrical center (UBEC) housing will expand causing the headlamp low-beam relay control circuit routed wire to bend slightly. After the wire is repeatedly bent it can fracture & separate. When this occurs the low-beam headlamps will not illuminate. As the UBEC housing cools & contracts the low-beam headlamp function may return. This condition dose not affect high-beam headlamps, marker lamps, turn signals, daytime running lamps or fog lamps.

That is the just of it.

So I would see if qualify for the recall. I received this for both of my C6 Corvette. First for the 2005 Z51 & next for my 2007 Z06.

Hope that help you out.

Mark

More infoThis is a GM Recall. Just got a letter for my 2009 Z06 and my 2013 Grand Sport. The recall states exactly what you stated your problem is. Call your dealer. They have to install a jumper wire in reference to the UBEC Housing.......(gets hot then cools and fractures a wire.) Had to buy the cars NEW in order for them to notify you, if you need, contact me and I'll send you a copy of the letter.

low beams not coming on.
 

I am the third owner of my 2005 C6 and got a recall letter for the wire replacement from the fuse box. get in contact with nearest dealer.