QuestionOk, so my parking lights and tail lights will not turn off. This was a rare problem and now it's an all the time problem. Took it to dealer, they did a diagnostic, this and that; said it's the junction box and they want about $500 to replace it. I'm not sold that's the problem, so I don't want to pony up that much and they're wrong. I've seen on other sites other Sonata owners having a similar problem. Is this something that is fixable or likely just need to replace the part. Right now I'm having to disconnect my battery every time I plan to be somewhere more than an hour. It's ridiculous. Any help would be great.
AnswerI haven't seen this problem, so I'm not in a position to speculate about the probabilities of what may be causing it. Additionally, I'm also not in a position to question the diagnosis of someone who has actually examined the vehicle and determined the issue.
On the other hand, this shouldn't be a difficult issue to diagnose while it's occurring.
Looking at the schematic, there are four reasonably possible causes:
1. Shorted lamp switch
2. Defective Body Control Module (BCM)
3. Stuck closed tail lamp relay
4. Wiring issue.
I'd start with unplugging the light switch. If this causes the lamps to go out, the problem is in the switch. If not, we can cross the switch off the list.
Next, I'd unplug the BCM. If this causes the lamps to go out, the problem is in the BCM or is a short to ground in the wire between the switch and the BCM. At this point, to determine which, with the switch still unplugged, simply test the wire between the switch and BCM for short to ground. If the lamps still do not go out, we can cross the BCM off the list.
Next, I'd check the wire running from the BCM to the tail lamp relay for a short to ground (with BCM still unplugged). If not grounded, then the problem is in the tail lamp relay, which is integral in the passenger compartment junction block. If grounded, the problem is that the wire is shorted to ground.
