2003 Silverado - OEM fog lights?

Hello everyone - first time poster here.

I have a 2003 Silverado 2500HD that is completely stock and the lighting is a bit tired and weak. I've been searching/reading on this forum and have decided to replace the headlights with fresh OEM units, put in good bulbs and possibly upgrade the wiring harness. The question I have is: are the the OEM fog lights are worth installing? I don't want them for fog but to give me wide and up close lighting for walk/jog pace crawling on forest roads and trails. I'm talking about when you're hanging your head out the window to see where your tires are going type of stuff - not more than a vehicle length or two ahead.

Perhaps some type of flood or utility lights pointed down & close would be appropriate but I'm looking for a clean and hopefully inconspicuous install. Can anyone provide their suggestions or experience?

Thank you in advance.

merwin said:

Hello everyone - first time poster here.

Click to expand...

Welcome to the CandlePowerForums!

The question I have is: are the the OEM fog lights are worth installing? I don't want them for fog but to give me wide and up close lighting for walk/jog pace crawling on forest roads and trails. I'm talking about when you're hanging your head out the window to see where your tires are going type of stuff - not more than a vehicle length or two ahead.

Click to expand...

That's really about the speed fog lamps are good for. However, how cheaply can you get the OEM fog lamps? Also note that due to the location of the lamps, they may not give that wide a field of view.

merwin said:

Hello everyone - first time poster here.

Click to expand...

Welcome!

I have a 2003 Silverado 2500HD that is completely stock and the lighting is a bit tired and weak.

Click to expand...

Probably so, being 12 years old.

I've been searching/reading on this forum and have decided to replace the headlights with fresh OEM units, put in good bulbs and possibly upgrade the wiring harness.

Click to expand...

All fine ideas; headlamps degrade a lot more with usage than many people realize. Not just lens deterioration (which can kinda-but-not-really be addressed by polishing) but also the reflectors gradually "cook". Make sure you get genuine GM lamps; there are a lot of slimy sellers on Ebay, Amazon, etc using weaselly language ("OEM style", "OEM replacement", "OEM type", "OEM [part number]") to sell aftermarket junk (and it is all junk). The correct ones are this one and this one.

Bulbs, use these for the low beam and these for the high beam (you'll have to trim one of the plastic tabs on the new high beam bulbs as shown here, but it's worth your two minutes of effort to get a whole lot more high beam light without added current draw or heat).

Wiring...well, installing relays will increase the voltage to the bulbs, but there is such a thing as too much of a good thing. Many GM charging systems tend to run at an especially high voltage (high 14s to low 15s), so even with some voltage drop in the headlamp circuits the bulbs tend to receive appropriate voltage -- keep in mind that as voltage increases, bulb lifespan drops a lot faster than bulb output rises. You might want to spend some time with a voltmeter before you decide yes/no on this.

With any set of headlamps and any bulbs, aim is far and away the most important determinant of your nighttime seeing, so it's well worth putting time, effort, and money into a proper aim job (not just "shine it on the wall and guess it's close"). Find a shop that has and correctly uses an optical aiming machine, take the truck there with your normal load weight and distribution, and have the lamps aimed as per these instructions. The headlamps on your truck are the "mechanical aim" variety.

are the the OEM fog lights are worth installing?

Click to expand...

No, not even slightly. They are useless, purely cosmetic toys, really not even capable of giving you much light for the walk/jog-pace lighting you describe.

Perhaps some type of flood or utility lights pointed down & close would be appropriate but I'm looking for a clean and hopefully inconspicuous install.

Click to expand...

You would probably be quite pleased with Bosch Compact 100 fog lamps.

Thank you very much for your speedy replies.

The abuse of the term "OEM" by vendors is maddening but I'll find a way to sort through it, Also, I found only about .2v drop at the lights compared to the alternator according to my Fluke DVM. I'll try the new bulbs before committing to a wiring upgrade.

Those factory fog kits are getting scarce and sound like they're not worth the trouble. Would the Bosch lights be best mounted above the bumper, inboard from the headlights, or low & wide in the factory location?

Ironically, I have a set of Cibie 275s, with the non-fluted lenses, in my garage leftover from days gone by which don't appear to be useful for what I want the Bosch lights to do. Would they be an appropriate addition to the upgraded stock lighting after the Bosch fogs are installed or would they be just more lighting "noise" when looking down a lonely stretch of rural highway?

.2 volt drop is almost meaningless.....what is the actual voltage at headlamp terminals with engine running and headlamps turned on?

merwin said:

I found only about .2v drop at the lights compared to the alternator according to my Fluke DVM.

Click to expand...

Did you measure that with the bulbs all connected, or at an unplugged socket? If you measured it with the socket unplugged, it's not a meaningful number.

Would the Bosch lights be best mounted above the bumper, inboard from the headlights, or low & wide in the factory location?

Click to expand...

I would put them in the factory location.

I have a set of Cibie 275s, with the non-fluted lenses, in my garage leftover from days gone by which don't appear to be useful for what I want the Bosch lights to do.

Click to expand...

Those are very powerful lamps if they're in good condition. Non-fluted lenses means they're auxiliary high beam "driving" lamps.

Would they be an appropriate addition to the upgraded stock lighting

Click to expand...

For sure!

I took the voltage measurement with the headlights on, engine running. It sounds like there should be more of a drop based on what I'm reading. This may be cause to check again, making sure my test points are clean enough so there isn't a skewed reading. No urgency to do this however, at least not until after the replacement fixtures and bulbs are in.

Once again, thanks!

merwin said:

I took the voltage measurement with the headlights on, engine running.

Click to expand...

And just to be clear: all headlamps were plugged in?

And to be even clearer: You're measuring the voltage such as according to this? This involves measuring each half of the circuit independently, not just across the bulb terminals.

From Daniel Stern Lighting
By Daniel Stern with special assistance from Steve Lacker and David Hueppchen​
This test must be made with the lamps switched on and all bulbs connected, so you may have to work to get access to the correct bulb
terminal. In some cases, it may be easiest to remove the bulb from the headlamp and (carefully) operate it outside the headlamp with your
voltmeter connected.
Connect the positive (red) test lead of a voltmeter to the car battery positive (+) terminal, and the negative (black) test lead to the +
terminal of whichever headlamp filament (beam) you're testing -- use the bulb farthest away from the battery. Your voltmeter will give a
direct reading of the voltage drop. Write it down. Then, connect the positive (red) voltmeter lead to the ground terminal
of the headlamp bulb, and the negative voltmeter lead to the negative (-) terminal of the battery. Your voltmeter will again give a direct
reading of the voltage drop. Write it down. Add the two voltage drop figures obtained, and this is the total circuit voltage drop.

Click to expand...

Measuring across the terminals of an empty socket, even with the other lights on, won't provide an accurate result. All bulbs on the circuit being tested, including the one whose feed you're testing, must be lit at the time of the test.

All headlights stayed plugged in and I slipped a probe into the back of the connector. I didn't check the drop from the negative lead to ground. Thanks for the link. When I set the time aside to revisit this, the test will be more thorough.