I've got an '04 Cav LS stick - Stress Intensifier Edition. Low beams don't work. High beams work fine and all the rest of the exterior lights (park, turn, etc.) work fine. In the inside fuse panel, the Left and Right Headlight fuses look good and test good. Headlights themselves look good (both filaments). When I release the parking brake, the DRL light in the cluster flashes and I can hear a relay clicking. After a few flashes the DRL light goes out and the little wrench symbol comes on (which the owner's manual says might be a stuck DRL relay?)

I've seen a lot on pre-'00's here and wondering if the '04 is the same. Where is this DRL relay that might be stuck? And could this be a bad headlight switch?

Thanks in advance for any advice from the more experienced.

there is a drl resistor in the left front bumper area, looks like a white magnet almost. that may have gotten fried. Just keep the stock bulbs on these cars man, those high intensity things cause more problems than they are worth. the wrench symbol is there to tell you that the headlamp(s) are inop, and the drl indicator flashing is the same thing. They relay could be bad, if you can get to it, jump it using a paperclip shaped into a horseshoe, remove relay, insert paperclip. if the lights work, replace the relay, if not, replace the resistor. the resistor is not easily acessable, so a shop might be in order, but at least you have a lil insight.

Well, I appreciate the insight but it turned out to be a wire corroded inside of the insulation with no indication outside that anything was amiss. Not just any corroded wire mind you, but a corroded wire on the female side of the plug under the battery where the wire goes into the backside of the plug. Spent a grand total of just about 8 hours finding it. After replacing the headlight switch ($108 a the local B-to-B) and the DRL relay ($12 at the same place) without success I was in the process of testing conductivity and resistance on every wire from the male side of this plug to the end terminals (that plug into the serviced component, such as headlights, etc.) Along the way, the third time I disconnected the plug the wire finally separated, so it was just dumb luck at that point. Otherwise I would have been testing wires from the female side of the plug to the main wiring bus.

The wire in question is the dark blue that goes from the plug to the "A" terminal of the left headlight and continues on to the "A" terminal of the right headlight (and you have to remove the wire guide on the back of the headlight plug to see the "A" cast into the plastic.)

The DRL resistor was OK, however the epoxy filler is starting to crack so I intend to replace that ASAP. '02 to '07 Saturns had a recall on this part because of cracking and moisture penetration so the problem is out there.

Once again, thanks for the input. A good, stable multimeter is your friend.

Nice work man, electrical problems are the most difficult to diagnose IMO, even a good meter can't trace a needle in a haystack, it's all about luck sometimes, 8 hours or 8 minutes, I hate it.

Spend the time and re-route the wiring harness the correct way next to the radiator instead of sandwiched between the washer fluid bottle and the frame. Believe it or not, GM TechLine shows the correct routing even though they come from the factory crushed behind the washer bottle. Corrosion and broken copper inside the harnesses are common on the harnesses exposed to the elements.

Thanks to all for the help. That loom routing looked wrong to me. Why would you crush a bundle of wires. Good advice to re-route, so I'll make time for that. Sounds like big fun. While I'm at it maybe I'll figure out how to protect the plug under the battery also. Something other than spraying it down with battery grease. (Too much of a mess for the next time this plug is involved in something.)

I don't think the plug itself will cause any problems. The plug is weathertight. When I repaired the front lighting harness, I just used a little dielectric grease on the seal on the male side and plugged her in. I also moved the ground from under the battery to the same bolt that the negative battery cable is bolted to on the battery tray. You're probably going to need a bigger eyelet to change the ground location. If I remember correctly I just took a round file to open mine up. Harbor Freight carries heat shrink tape which is great for harness ends and wire loom. It's a little on the expensive side but it's worth it.