93Xtra-Cab

I bought fog lights from Walmart because I'm cheap. They were $20. I put them on and they were terribly dim. They came with a 55w H3 bulb. I went on eBay and bought a couple 100w H3 bulbs and put those in. Very little difference. It was wired to the ignition so I tried wiring it directly to the battery. No change (I kind of thought so). My dad suggested to wire up a relay, but I thought that would just make it worse. I'm not a wiring expert so I'm not really sure what to do next. If I can't figure out why they're so dim, I'm just gonna take them off smash them with a hammer and buy something better, preferably not from Walmart xD Any suggestions?

4Crawler

iTrader: (3)

Measure the voltage across the bulb terminals when the lamp is on and see what it reads. If that voltage is not within 0.5 volts of the battery, find out why. You can measure the battery "+" terminal to the bulb "+" terminal voltage drop and likewise the battery "-" terminal to the bulb "-" terminal voltage drop. Could be a bad ground or power connection:
- http://www.4crawler.com/4x4/CheapTri...ml#VoltageTest

I run the 100W H3 bulbs in my Hella fog lights and they are much brighter than the old 55W bulbs I used to run.

93Xtra-Cab

I didn't think of that. I have them grounded on the lower valance where I have them mounted. That might be the problem :o There is a bolt with a few wires grounded to it up in the engine compartment. Maybe I should try running one up there and see if there's a difference. Thanks!

4Crawler

iTrader: (3)

Yep, 2 side of every circuit, power and ground. Quick check is to grab a set of jumper cables and hook one clamp to the battery "-" post and the other clamp onto the bolt you used for the ground wire. If the light brightens, that is your problem. I prefer to run dedicated power and ground wires to my lights, with the ground hooked up to a known good ground point back close to the battery.

tj884Rdlx

if you grounded them to the valence, but the attachment of the valence to the body is pretty rusty, then you're grounding your lights through that rust.

also, always use a relay instead of running directly from a switch. otherwise, the power to your lights is limited by the amperage of the switch. use the switch to turn on the relay, and use the relay to turn on the lights. the switch may be on a 5-15 amp fuse, while the lights should be on 20-30 amp fuse.

make sure those sprawlmart lights can handle the heat of 100w bulbs. otherwise you may melt the housings or scorch the lenses, and all this work goes in the garbage after a while. 55w is the standard highbeam wattage, they usually are pretty bright.

93Xtra-Cab

Ok, I ran new wires to a known, functioning ground and it is alot better. I didn't like the switch that came with the lights so I used another one I had stashed away. I didn't think to check the amps. It was 2 amps. I checked the switch that came with it and it was 15 amps. But when I put both switches on there was no difference. The kit also came with a fuse built into the hot wire running from the battery to the switch. I can't remember what the amp it is off the top of my head, but if I changed it out to a larger amp, it wouldn't make it any brighter, right? I'm probably asking way to much for $20 walmart lights, but c'mon, they should at least function. I also don't see how a cheap light such as mine and something more expensive like a KC daylighter can be any different if they hypothetically have the same watt bulb. Is there something I'm missing?

4Crawler

iTrader: (3)

Did you check the voltage at the bulb yet? If not, do so. Why? You might have a 55 or 100watt bulb, but that is assuming it is getting about 13.6 volts at the bulb to get full current:
- http://www.4crawler.com/4x4/CheapTri...ml#VoltageTest

If you are getting say 10 volts at the bulb, you are only getting maybe half the light output:


And if you are getting good voltage at the bulb, then you know that you are getting the maximum watts out of the bulb and in that case, you may have a crappy reflector or lens on those lamps. I have a set of Hella 550 fog lights on my 4Runner and they light up everything in front, but I have some lower quality fog/driving lights and there is no comparison in light output. Same bulbs in both, both relayed and the only real difference is the reflector and lens.

93Xtra-Cab

Wow, I thought the light output would be a linear curve. Hmmm...learn something new everyday xD I have yet to check the voltage to them. I'll do that later today or tomorrow when I'm off work. I'm also going to put a relay on 'em tomorrow. The bulbs stated that they are 100w, but they are really cheap eBay bulbs, shipped directly from Hong Kong, $0.80 a piece...I probably should have gotten a better bulb to begin with. I might try putting the 55 watters back in just for kicks. I appreciate all your help and your patience with my silly questions!

93Xtra-Cab

Ok, i installed a relay on them yesterday and it made them even brighter! I couldn't be any happier even though I put in probably double the price of the lights in parts to make them work xD Thanks for your help guys