I will try to keep it short and sweet. I had to take it to a shop that figured that water getting into the trunk caused a short with the parking sensor. The parking sensor was removed. I have a few codes on the dashboard that the mechanic wasn't able to figure out. He said that he went through each and every fuse, next he could go through all the wiring. My issue is my tail lights. They come on but when you hit the brakes they dim and when the put the turn signal it doesn't work normally. I have already checked the bulbs. This happened once before and I took to a shop that specializes in electrical problems, but it is no longer there. By the way, it's an 04 S-type 4.2. Thanks

 

Could be a grounding issue with one or both of the taillight assemblies, which is not uncommon in these cars. Some of us have had to remove the assemblies, clean them, burnish the bulbs and bulb sockets, then reinstall them. The assemblies are metal, so lay an old towel across any exposed metal panels in the trunk as you remove and reinstall the assemblies to prevent any shorting. I had to do this to my 2005 S-Type quite a few years ago, and it solved the taillight issue I was experiencing at that time....

 

Thanks Jon89, I will try this. I couldn't find any info regarding this issue and as soon I posted this a bunch of related topics popped up at the bottom. I see this is a common theme.

 

+1 on grounding issue

 

How much water? There are some modules in the trunk that may have been damaged if too much water got it.

I'm also curious about the "short" with the parking sensor. If a sensor got wet, I'd think it would return to normal after drying out, but am not positive. That's what has me wondering about damage to the control module.

Wiring diagrams are here:

JagRepair.com - Jaguar Repair Information Resource

Re: The grounds for the taillight modules. I'd have to dig a bit deeper, but i think the lights have a constant power supply and a switched ground via the control module. This is backwards from most vehicles that have a constant ground and a switched power supply.

 

Honestly, it couldn't have been more than 1-2 inches of water. I saw that the parking sensor that lives next to spare tire was sitting in some water. I removed the spare tire and found a drain plug located at the bottom. I disconnected the sensor and removed it. I saw some rust on it. I replaced the parking the sensor with one I purchased from EBay. The dreaded water in the truck strikes again.

 

Maybe the water level had already leaked down somewhat when you saw it? Perhaps it had been much deeper previously, deep enough to do some damage.