I have a 2005 300 (garden variety, 2.6L).. the fuse for the running lights blows after driving for 20minutes or more and turning off the lights. When restarting the car within about 10 minutes, the fuse will blow. Driving for less than about 10 minutes or waiting longer than about a half hour seems to negate whatever is happening, and the fuse stays intact. They do not go out while driving, the past 3 times it has happenend, I've checked the lights before shutting of the car and they're on, then after restarting and getting out of the car to check, they're not working. The brake and turn signals still work, but no running lights. I tried replacing bulbs thinking maybe they're just old and drawing too much current when they're hot, but I've replaced the tail light bulbs, and the front turn signal and side marker bulbs (but not the peanut bulbs next to the t/s bulbs in the front).

Anyone run into this? The dealer has found no problems and replaces the fuse and says all is well. But after a half dozen fuses, I'm thinking ehh, maybe not.

 

Try leaving bulbs out one at a time to see if you can isolate the problem to one bulb's circuit. (That will take some patience and a boxload of fuses probably.) If you gan get it down to a single circuit, then you'll need to inspect the wiring in that circuit very carefully for a short. My guess is that there's an intermittent short (maybe a wire that has been rubbing against some metal but doesn't touch all the time). If you get lucky enough to find it, some tape will probably clear up the problem.
The trouble with something like this is that it's a big time consuming job to find the problem, but it's not rocket science, so you can do it as well as the dealer mechanic at $85/hour.
If you find the circuit but can't find the short, consider just bypassing the circuit with a new wire.
Good luck.

 

have u been in a fender bender at any time or bumped into anything?

 

Yea... this was going to be my next course of action if nobody had any better ideas or had maybe seen this before. But it's going to be a bummer driving around with one light out at a time. The wife won't be happy about that. 'course, I guess if it means that in the long run, she's not driving around with NO running lights at one time, then it's a win.

But it's bugging me, cuz I'm just not sure it's a short. That and there are ... what? 15 bulbs on that circuit? 3 under each headlight, 2 front sidemarkers, 2 rear sidemarkers, 2 tail/turn/brake bulbs, 2 reverse lights and 1 or 2 license plate lights.(I haven't checked those yet). That's a lot of 30 minute trips while missing a one bulb at a time!

thanks for the suggestion!

Never any accidents. Never bumped anything harder than just scuffing the lower rear bumper on a parking curb.

 

"scuffing the lower rear bumper"
this is what I was looking for there are wires that run along the back of the bumper for the tail lights take out both of the tail lights and look down there see if the harness has been pinched between the bumper and the frame seen it a few times where they cut through and short out fuses for the light,brake light and so on.

 

Thanks for the tip, I'll look back there. But the "impact" was below the license plate and literally just a 1-inch scuff that I buffed out with a rag and some brake cleaner. If that tiny of an impact cause a wiring short, then there is a serious mis-routing of wiring going on with the 300.

As an update, the wife took the car back to the dealer, where they proceeded to install 5 in-line fuses to further isolate the circuit in the hopes that one of the fuses would blow and point to a particular corner or the license plate bulbs. Then after 2 weeks of no fuse blowing, they called her and told her to bring the car back in and they removed all of the in-line fuses and charged her $100 for "diagnosis time". The car isn't under the 3/36 warranty anymore, but it does have a Chrysler "Care Plus" warranty. When asked why they are charging her the deductible for the warranty when there was no difinitive fix they just said that they were "pretty sure" that it was just a wire shorting on something and that moving all the wiring to install the in-line fuses moved the shorted area off whatever it was contacting and there would be no further problems.

I say BS, but the wife already paid the bill.

 

And to add insult to injury, the running lights stopped working again. Now the fuse blows about a half second after I put it in, it doesn't take any drive time at all. I put in the fuse, the lights come on and then the fust blows in about the time it takes to say "Wellll?"

So I think I'm looking for some sort of exposed wiring, since the first time it happened was after driving through some rain, and it started up again yesterday after driving around in slushy snowy conditions. Not that it hasn't been driven in the rain since it was "fixed", but who knows? We don't drive it a whole lot and if it did get driven in the rain, it wasn't for a very long trip.

Anyhow, thought I'd update, see if anyone had any new ideas.

 

My problem ended up being that the harness for the license plate light was routed incorrectly and was resting on the muffler, which caused it to eventually break the two wires and then the power and ground wire corroded together. So a little snip of the wire to get rid of the corrosion on each end, a couple of wiring butt-connectors and some shrink-wrap and all the lights are working again. Oh, and I re-routed the harness behind the heat shield so that it won't come to rest on the muffler again. Taking the rear bumper cover off made it a whole lot easier to get at the wiring and re-routing it. And since it's only held on by 2 screws in the wheel well and about 15 plastic clips, it only take a couple minutes to get it off.

 

so it ended it being it the area that i told u about almost a year ago

 

dont ya just hate it when people dont listen/follow directions that are rational and pragmatic.