I have a 2004 mercury grand marqui with 187000 miles on it. It has a v8 with an automatic transmission. The tail lights do not work during the night time. The brake lights work when you press on the break but the tail lights do not remain on when you let off the brake. It started last summer and stopped during the winter, but started back this summer. I think it may be a wiring problem. Im wondering if the temperature has anything to do it. Do you have any suggestions on what the problem might be? No other problems with the car, it is very clean and runs great.
My guess since its temp related is exposed wiring but without being able to dig in there there's no way to know for sure. Scotty has video's on what to do for lights acting up and videos on trying to chase down bad wiring so check the channel for those video. Hope that helps my dude
I would use a test light to determine if you have power in the rear of the car. Pop out the sockets and put the ground lead of the test light on the body of the car and then touch the probe to the terminals in the socket. ONLY the PARKING lights should be turned ON. Check to see if you have power in the rear on the brown wires. Brown in the ford and gm are the parking lamps.
Next check up front. Is the rug worn where the drivers feet are located? If so, pull up the rug and inspect for broken wires. Yes the rear tail lights turn signal and everything else runs through that floor area on the left near the kick panel. Look under the rug for evil.
Check the brown wire coming down that harness at the connector on the kick panel or under the dash. Does it have power? If not its a problem up top with the switch or fuse. Dig for it.
The switches on these are weak and fuses can look good but be blown. I don't remember if the CV has a rear fuse for the tail lights separate from the front or not. Look for it.
Ford has an excellent schematic in the vacuum and electrical troubleshooting guide (manual) for your car. Find a copy, even electronic to refer to. This will help your mechanic should you not be able to solve the problem.
- Thank you guys very much. I stumbled apon a recall for the mercury grand marqui wile looking thru diffrent videos after checking the fuses and relays. The recall is for a LCM moduel. I located mine and moved the wiering around and tapped the moduel a couple times. The lights began working. Though they stayed off when i turned the car off and on again. I guess ill make an appointment to have it changed for free. i just found scotties channel. I love the videos. I have been beng watching them. Thanks for the fast response.