both of these went out a few months ago, have been using the rear fog lights as tail lamps and limited night driving due to this. I have tried to find something online to try to resolve this issue. Sounds like most people are saying the ground may be bad? what am i looking for and about where will i find where these are grounded? also some people say non factory bulbs may be causing this. can i fix this on my own? also i have heard a "hard reset" (unhooking the battery for 5 minutes may work.) as you can tell i have done my research, i was just hoping someone had a more definitive answer for me. anybody else have this issue? how much was it to take in and get fixed?

 

This doesn't sound like a very difficult problem to decypher, where have you been looking online?

Make sure you check every other exterior light on the car, and the dash lights, and give me the full inventory of what's not working. Then I can look on a wiring diagram and give you points to test, but I can't tell you if you will be able to fix it on your own or not.

 

well here is the rundown.

lights that are out:

1.) tail lights
2.) tag lights (which i think are connected to the tail lights in some way)
3.) the lights on the center console i.e. the radio and a/c lights
4.) front left turn signal (light is only not working because i hit a pole and it knocked the light and cover out) entire oval light needs to be replaced.

i just wanna get my tail lights and tag lights working for legal purposes. : ) when i was getting my belts and oil replaced today I had them look at it, but they said i may have to take it to an import store. I am pretty handy, so if i can just figure out where to look and what i am looking for i can most likely fix the lights, even if i have to rig them.

also, i have another question for you.. my drivers side door handle popped on the interior and no longer is working, i was gonna have them fix it at the shop today, but they quoted me $800 to fix it. without it working i have to use the exterior handle to open my door (by rolling down my window) is that interior door cable hard to replace?? they said the latch and everything was still good, i just need to replace the cable part. any ideas?

i know this sounds like a bunch of issues, but i let them compound on me. so here i am asking questions while someone is willing to help answer. hope to hear back from you.

 

Brake lights, reverse lights, turn signals all work?

 

May need to give the security and locking module a ford handshake . Its under the fuse box in the trunlk

 

all brake lights, reverse lights, and turn signals all work. its just the tail lights, and the tag lights..????? confusing..

 

what do these have in common with the tail lights?

 

It's helpful to know what's going on (or not going on) before sitting down with a wiring diagram and a magnifying glass to look for common denominators. In this case, there aren't any.

First point is the grounds, they are separate for each tail lamp assembly, and poor connection would affect the other lamps in each cluster. Ruled out.

Second point is that the tag lights are fed from a relay in the trunk fusebox, but a fault with this relay would also kill all four of your sidemarkers. Since you didn't mention them, I'll assume they are working: the relay is ruled out. There is a separate fuse for just the tag lights, #19 in the trunk fuse box, 5a fuse. Check it with a testlight, it will probably be fine.
Then check at the tag light bulb contacts for power and ground (lights turned on). The easiest way to check for ground is to clip your testlight to the positive battery terminal, then anything you touch that is a ground will light the light. You'll have a ground, but no power when you clip the testlight back onto the negative battery terminal and test at the tag lights. Now we have two places to look:

There is a diode in the harness for the tag light feed, adjacent to the battery, red wire in and red/white wire out. If you have not had a battery fizz event, there's probably nothing wrong with it, but you should have power on both sides of the diode.

The most likely cause for the taglight fault is a broken red/white wire in the harness at the right trunk lid hinge. The wire is either open circuit, or if the #19 fuse was blown, it is broken and shorted to ground. The harnesses fail regularly at this point where they flex, and can also disable the trunk lights, trunk release button, etc. Likely that this is where your problem is, and is unrelated to the rear park lamp fault.

The rear park lamps (tail lamps) are fed directly from the body processor module. They are wired separately, two separate outputs. Test for power at the red/ white wire (right tail lamp connector) and red wire (left tail lamp). If you have power there, somebody jacked up the bulb sockets by jamming the wrong bulbs in. If you don't, best have a look at a few fuses. Left side heel board fuse box (driver's side, below the forward face of the rear seat cushion), check #5 (15a) and #7 (15a). Right side heelboard #3 (15a). Those are all feeds for the body processor module, I don't know which might do in the tail lamps, but I know I would test them all with a testlight. If you have power through the fuses, but none at the tail lamps, it's looking like a bad body processor module. There are two connectors in the harness from the BPM to the tail lights, but if I was working on the car I would just go straight to the BPM and test at the red and red/ white output wires at the source. It's a big box behind the glovebox, under the dash on the right side.

If the fuses tested OK but you have no outputs at the Body Processor Module, the BPM is bad. You're going to have to replace it if you want the lights to work and eliminate the rear bulb fail warning. I would not try splicing the wires for the tail lamps to another power source, you will only overload those circuits. You could switch the orange rear fog light wires at the tail lamps with the red and red/ white park lamp wires, and leave the fog light switch on: but that really doesn't accomplish much, you'll just be lighting one bulb instead of te other, and still have a failure warning. Send me a private message if you want a good used BPM, we'll compare some part numbers and make sure mine is compatible. It won't be cheap, however. I also have tail lamp bulb holders if those are damaged. Good hunting!

By the way, what is the answer to my question about your other sources of information?

 

There's another nice piece of work that didn't even get me a thanks, let alone an answer to my question in return. Another lesson learned.

 

i just got done doing some of the things you mentioned, to no avail. Thank you soo much for taking the time to answer my question with such detail! amazing. If changing that relay doesn't work I am gonna take your email to my body shop guy and have him test my BPM. however, i finally did realize that yes my side markers are not working either. which relay is it, because that is most likely what is keeping the tag lights and the side markers out? Again, I do apologize for my delay in reply, I was in the process of moving from florida to georgia, so i had to ut of my car projects for a few weeks.

 

I'm telling you what dude, you **** me off. Just another case where I did a bunch of work based on bad information, when I begged for the goods. I run out to my shop and stare at wiring diagrams through a magnifying glass to try to answer your question, and you can't even figure out whether your lights are on or off?

 

sorry, honestly, i didn't know those side markers lit up, i thought they were reflectors until i saw them working on another car. sorry, for wasting your precious time. not all of us are professionals, and not all of us work on these cars everyday to take time out of our schedule to immediately run out and try all options you gave. I do appreciate all your help, i must have overlooked one simple thing. have a good day.

 

i still cannot figure why you answer questions here considering most people on here are amateurs and not professionals. don't take it so personally, thanks for your help though. maybe it will help someone else out sometime.

 

hey there! I have this same exact issue.

and in answer to this:
JagtechOhio Brake lights, reverse lights, turn signals all work?


yes they all work. this is the same identical issue.
by the way Im a system engineer so I work on data center equipment all the time. so I certainly understand the schematics that you have outlined here.


in reference to what you posted Ohio:
all four side markers are not functioning either.

 

savhomer... was it the relay after all? if so... which one?

or jagohiotech? please feel free to chime in.

 

whats not working:

all park lights. side markers. fog lamps front. dip beam lights /w fog lamps.
no radio/ac lights.



I'm thinking a relay?

 

oh yeah 1998 XJ8 VDP 55K miles on it. sucker is like new.

 

Mannybz

You're replying to a post a year and a half old. I don't think these guys are active anymore. Also, the reference car is out of place on this X350 forum. Suggest moving over to the correct year/model X308 forum so like minded owners can engage with you.

Best,

 

Yeah I did look at the time stamp on the forum but you never know. I did a generalized search across the forum and for the most part the electrical platforms are relatively the same across the benchmark for the X308 and X350 with some minor enhancements on the X350's system. but I did also post my issue in the X308 forum as well.

 

Hey I was hoping you could help me. I have a XJ8L 1998. I lightly bumped into a wall while parking and now my license plate lights and left rear marker light will not come on. I replaced the bulbs above the license plate and still no light. I cant honestly say that I know the lights were working before I bumped into the wall. Your help is very much needed and judging from your previous responses, Your one of the best in my eyes. I really need your assistance, I cant believe all of the trouble I am having with a light for a stupid license plate. Yuk!