papcie03

It may be time for me to find a new dealer. They are telling me that the bulbs are on backorder (not surprising) but that they can't order the bulbs until they are back in stock. I'm not sure exactly how GM's stock system work, but it seems to me that they should be able to place an order on a back-ordered item and that it will ship when it is available. This is the same dealer that when I originally went in insisted on checking the headlight aim before going any further. They didn't use any kind of procedure and just aimed them down until and I quote "they looked good against the wall." When I checked them, the pattern was almost 18" below the spec in the PIT procedure.

I checked the bulbs last night and they are seated properly. I think the dealer might have aimed them with the high beams since they are dead-nuts on with the center of the headlight at 25ft. Comparing the top of the beam pattern between high and low beams is 17-18" difference. That difference is what is causing my issue. When the dealer does the aiming procedure properly, it will move the low beam pattern up but the high beams will be 17" higher than that which will just be pointing to the sky again. Unless the new bulb significantly changes the beam pattern.

I spoke with the dealer today and they've agreed to do the update now. I'm probably to much a softy with them but hopefully this makes them better. Luckily I don't use the high beams that much anyway.

Thanks for taking a minute to respond. I know about the headlight design, I'm just wondering if anyone else has high beams that are so much higher than the low beams that they don't do anything to add to the distance you can see at night. I'm hoping that maybe there is something wrong with my headlight housings that are causing the extra light when the high beam shutter opens to be so much higher. Parked 25 ft from a wall, the extra light is centered 18" above the top of the low beam hot spot which means they just light up the tops of trees. I'm sorry if I'm coming across a little whiny but most of the posts on Sierra headlight issues focus on them sucking in general and not this specific problem. If everyone else is experiencing this issue, it's clearly in the crappy design but if I'm the only one, it gives me some ammo trying to get it fixed with the dealer. So the next time your driving at night, flip the high beams on for a second and let me know. Thanks

Getting ready to call the dealer again and hoping someone can help me out. How much higher is the beam pattern with the high beams compared to the low beams on your trucks? On mine, when the low beams are aimed according to the procedure, the high beams hot spot is about 17 inches above the low beam hot spot. This makes the high beams do nothing but light up the tree tops. Does anyone else have this problem or maybe there is just something wrong with my actual light housings. At this point, it seems like my options are to have functional low beams OR functional high beams due to this aiming discrepancy. Anything to help me clarify my issue before talking to the dealer is appreciated.

Just went in today to get this done and the dealer was completely unprepared even though I explained everything over the phone. I mentioned that when I had the high beams on that they are aimed so high they only light up the tree tops. I probably should have kept my mouth shut since they then insisted on aiming the lights and trying that before doing the update. I'm not sure what procedure they used to aim the headlights, but it definately wasn't the procedure in this TSB. I just parked 25 ft from a wall in my parking garage and the low beams hit the wall about 2 ft below the headlight height on the truck vice the +0/-.75" in the TSB. The high beams were useless before but now the low beams point right into the ground (although I'm sure the high beams work great). If this is in fact the proper aim point, no wonder everyone is complaining.

Sounds like this will at least help with the low beams, but does it do anything with the aim on the high beams? I have a feeling that's more a symptom of the projector lens design vice the bulb. I know on mine, the high beams point to the tree tops. Aiming the high beams to be functional gets the low beams pointing right into the ground.