My daughters 2006 magnum se has had intermittent problems with brake light fuses and taillight fuses blowing. The brakelights haven't blown in a while now. But the taillights will blow sometime during the course of the headlights being on. Also somewhere in the mix the left rear turn signal stopped working tried a new bulb still does not work. No power at the socket. So I traced the wire all the way back to the power distribution box up front, behind the front control module. There is no power out of the wiring harness. So I pulled the plug and tested, no power out of the distribution box. I compared against left front, right front, and right rear. All had power out of the distribution box at the plug. Does anyone have any guesses to what the problem might be. I'm leaning toward the front control module. But don't know enough about it to be sure. It looks like it could be pretty spendy.
Would appreciate any help I can get. Thank you

 

I got your PM. First questions I need to ask you. One, are all the bulbs the proper ones that should be in there? Two, is there any aftermarket alarm or stereo equipment?

Here's how your exterior lamps work. When you hit the brake pedal or use your turn signal, there is a message (request) sent to the front control module.... that's the silver rectangle box with 4 screws on the front of the fuse box under hood. The IPM is the black box it attaches to. The FCM recieves the request and uses the IPM to do the work. You will just be chasing your tail trying to figure this out if you don't have the proper tools and info. The only thing hard-wired is going to be your center high mount stop lamp. I hope this clears a few things up for you.

 

No aftermarket alarm or stereo equipment. All bulbs are either factory or oem replacement from a local parts store.

 

OK, all of the wires that go to the tail lamp assemblies are bundled together from the front of the car all the way back. The turn signals get power from the IPM, BUT..the FCM is what controls them. The turn signals are not fused. There is a driver in the FCM for them. The brake lamps are the same way (outside ones, not center high mount. Center is on a hardwired circuit) Tail lamps are also powered by the FCM/IPM however that circuit has a fuse. Are you confused yet? Well, it gets better. The wiring diagrams are way off base too. What you need to be looking for is an issue with the wiring harness or some water in the PDC in trunk. Something is touching somewhere. Yes you will probably have to take some interior trim out. The wiring bundles are under the carpet about 2 inches from door sill openings. Now, as far as the no power to the turn signal...you will have to get a new FCM, the drivers probably won't reset even after you find your wiring problem.

Yes, this is an incredibly stupid way to operate exterior lighting. Even if the module powers something there should still be a fuse. You can't effectively diagnose a circuit when the module shuts half of it down and no way to repeat the condition without killing a new module every time. I'm still battling with one in the shop.

 

Thank you for your response I have not had a chance to look at the car again either she is gone to work or I am not around but I do appreciate your help. And will get back to you when I am able to tear into it. But what your telling me is I have to isolate the tailight problem before I replace the FCM. The FCM can not cause the tailights to blow the fuse correct? Why would I be looking for water in PDC in the trunk. The fuse for the tailights is in the engine compartment? I do know for a fact though both are dry. How you doing with the one you had in the shop? Thanks again. I will be getting back to you when I am able to take a look at the car again. Until then keep replacing fuses, getting close to about 20 or so by now...

 

The FCM does control the park lamps. FCM gets a signal from the headlamp switch then sends power to the park lamp relay. I will get you a layout of the relays and post it here. Yes the park lamp fuse is in the IPM under the hood (it should be) Magnum may be different i'll check. The FCM is not the load on the fuse, the wiring circuit to the rear lamps would be the load blowing the fuse. Something is shorting somewhere.

The one in the shop is still here. Te case has been escalated to Detriot. More to come...

 

Hi well I finally got a chance to tear into the magnum. I removed both tailights, replaced the fuse, turned on the lights. There is a wiring harness that goes below the R/R tailight assy. I wiggled it around and the fuse blew. I pulled up the harness as far as I could and noticed kind of a melted portion of electrical tape. Pulled it apart and found 6 wires melted together. In pulling each wire apart I found portions of bare wire. Also found a wire broken off the main plug to the harness, luckily its on the side that needs to be replaced. Just so happens that the broken wire is to the left turn signal Called dodge they don't stock the part 5059132AA Thank you I really appreciate your time and help.

 

Yes, seen that a couple times. The wires were a little too close to the exhaust? BTW, there are connector kits available through Chrysler. They usually come with some new wires and some heat shrink.

 

I just went ahead and cut out the bad sections of wire bared the ends twisted them and sodiered together used some heat shrink tubing and taped them. As for the broken wire I just removed the terminal from the plug and sodiered it back on. Works good as new. Thanks again...