Why does my DRLs have two fillament?

[NSXTC]

Is it mine only or does yours have dual fillament as well? This doesn't make sense.

If this is the case, any 3157s will fit and does not have to be a special one as someone posted earlier.

[NSXTC]

Is it mine only or does yours have dual fillament as well? This doesn't make sense.

If this is the case, any 3157s will fit and does not have to be a special one as someone posted earlier.

[Hum2]

NSXTC...David:

I questioned the 2 filament DRL's as well, They don't run when the headlights are on, when does the high/bright filament work? My guess..it should have worked when the headlights turned on.

I wired my DRL relay to my parking lights relay as you previously spec'd. I will wire a switch when the weather warms up this spring.
Thanks,

Ric
OMAHAOG

[MAC]

I have some hands-on experience with different types of 3157 bulbs, one online auto parts seller sent me 3157 with very different base, packaging says 3157. If you do a search on 3157 bulbs on eBay, you will see at least 3-4 types of very different base designs, (but none as the wrong base online seller sent me). In auto supply stores, there are 2-3 types of 3157 followed by 1 or 2 letters, 3157LL or 3157L, etc.. In addition to the different bases, there are our round glass bulb, LED tip or small glass bulb type, I think LED tip should work just as big round glass(as stock 4157), but not sure if small glass bulb will work in Hummer. Note: our stock DRL bulbs are 4157s=3157.

Bottomline, if you buy 3157 that looks like our stock bulb, you'll be fine.

[ChuckE]

On my H2, with 4157K DRLs in place, I found that the higher output filament is already being used. You can easily wire in the 2nd filament by putting in a jumper at the bulb plug.

The 2nd filament would use just 0.6 amps vs. the 2.23 amps of the main filament, the one that is in use. The additional 1.2 amps (having two lamps wired) is not going to exceed the relay already used to power on the current filaments).

You will notice a colored wire on one lead and a black wire on the other lead, with no wire on the center lead. Just connect a wire from the colored (the non-black) wire to the center connector.

BUT, it really is not going to gain you much. According to the spec of the 4157k, that 2nd filament is only about one tenth of the light output of the main filament (3 ft/candles vs. 32 ft/candles).

You will probably not even notice an additional 10% more light output. Forget it.

[DRTYFN]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by MAC:
I have some hands-on experience with different types of 3157 bulbs, one online auto parts seller sent me 3157 with very different base, packaging says 3157. If you do a search on 3157 bulbs on eBay, you will see at least 3-4 types of very different base designs, (but none as the wrong base online seller sent me). In auto supply stores, there are 2-3 types of 3157 followed by 1 or 2 letters, 3157LL or 3157L, etc.. In addition to the different bases, there are our round glass bulb, LED tip or small glass bulb type, I think LED tip should work just as big round glass(as stock 4157), but not sure if small glass bulb will work in Hummer. Note: our stock DRL bulbs are 4157s=3157.

Bottomline, if you buy 3157 that looks like our stock bulb, you'll be fine. <HR></BLOCKQUOTE>

Hands on experience doesn't mean shaking hands with the service writer after getting your bulbs changed. I so don't miss the idiotic elitist attitude.