QuestionQUESTION: Hello. The tail lights on my 2005 300c just recently stopped working. The brake brake lights come on when I hit the brake pedal and the reverse lights show as well. From some of the research that I have done indicates taht it could be the fuse. The manual does not show an actual fuse number but I was wondering if there is an actuall fuse and if it is something that I could change myself. I have gone to two dealerships and they insist on hooking my car up to a diagnostic system for over an hour. If this has to be done I have no problem with that but if I can try a cheap fuse first, I would like to try that. Any suggestions.
Thanks.
Nickolas
ANSWER: Hi Nikolas,
It is fuse 8 (15 amp) that provides the current for the parking/tail lamps via the parking lamp relay in the same box under the hood. So take a close look at that fuse, and if it appears to not be blown or have crack in its wire then have a helper turn
'on' the lamps and feel/touch the relay to see if it clicks "on" or not. Then verify that the lights are working or not at the front and rear of the vehicle.
Let me know what you find.
Roland
---------- FOLLOW-UP ----------
QUESTION: Roland. Thank you for your advice on the fuse. It was the fuse and it was it quick (and cheap)fix. After I changed the fuse I started the car and checked everything and all was A-OK. Several hours later, when work was done I went to go home and I went to start the car and I wouldn't turn over. There was power going to all of the extremities ( steering wheel radio controls, signals, high beam controls etc)but the car wouldn't start. So I boosted the car. It started no problem, but my radio controls on the steering wheel, high beams, widows and signals wouldn't work. Should I have disconnected something before I boosted the car? I have never bosted the 300 before in all of the years that I have had it. I started it this morning and the same problems still existed. Is there something I can do to reboot the system on my own or is this a shop thing? Any suggestions would be greatly appreciated.
Thank you.
Nickolas
AnswerHi Nickolas,
That is an unusual situation. There is nothing in the manual about jumping that is unusual except to not have the voltage source exceed 16V. I am trying to find a common device that is involved with the radio controls on the steering wheel. the high beams, the power windows, and the turn signals. See if there is anything else that is 'out' and let me know while I look. the fact that the battery discharged after you put in the fuse suggests that there is something turned 'on' when the ignition is 'off' that did that. It could be the tail lamp circuit or any numbe of items that are called ignition off draw devices. Did you perhaps leave the parking lamps 'on' when you replaced the fuse? I would be inclined to use an amp-meter to see what the current draw is when the ignition is off and all the lights are off, and the doors are all secured. It usually should be 50 milliamps or less when measured say 30 minutes after securing things. Because the battery is in the trunk, the trunk light will be 'on' so remove its bulb when you make the measurement by putting the ammeter in between the - post battery clamp and the - post itself. Let me know the 'draw' and I will try and figure out why those other circuits are 'out'.
Roland
PS: The various circuits that you listed as not working are disparate except for one thing; all are mediated by the integrated power module, which now includes the body computer within that main box.. So I would suggest that you look closely at all the fuses in the box as I can't be certain exactly which ones are involved with each of the faulty circuits without a fairly laborius search through the pages of a manual I have on CD, which is not very reader-friendly. You may find a single fuse or several fuses that have a wire that is cracked or blown.
Thanks for the rating and nomination. Let me know what you find in the fuse checking effort.
