Hello to all of you Jag fans and fixers!

First, been coming here for almost 3 years, and have nothing but good things to say about the site, and people that help!! Of course, with deploying and such, i have had a couple of different accounts deleted and remade haha no big...

Ok, this is going to be as detailed as possible... So in Dallas, we have had some extremely cold weather hit us, snow/ice... so i get out of work, about 11 pm and its FREEZING! i start up the baby, let her warm up all the way (as dial guage indicates engine temp), then turn on my AC/heater and drive home (about 15 min drive)... i get home, park, and as soon as i turn the key to turn off the ignition, the lights just go out, not dim out. i said, ok i blew a fuse or something, went inside because its too cold to mess with. the next day, i turn on the car to make sure it works, heater/AC "comes on" but doesnt blow any air whatsoever. i find the blown fuse, F99 mini 10, and after replaced, lights come back on and the heater/AC starts to blow air, fixed right? WRONG! haha ... well now the lights dont go out at all. after driving, they dim but dont go out. i have tried unhooking the battery terminal for a whole night to reset any kind of "stuck" switches, reconnected in the morning, but problem still there. tried messing with the master switch on the overhead cabin light, nada. im thinking about a door or boot switch, but nothing displayed on the dash to indicate any of those are open. i think it might be a bad relay like a pin is "stuck" open and wont break the circuit but i dont know how to check that (how would you check that?). so, fellow thinkers and fixers, where would the next place be to check? i removed the fuse, F 99 mini, to keep my battery from dying. also, the 40 min battery saver function doesnt work for me, the lights stay on after i let it sit for like an hour or so, but i will put the fuse in today and actually time it, or just come back in an hour and check it. So can anyone, explain to me, how the lights work, as far as where the components for the system can be found? i.e. what component controls the cabin lights to shut off after 15 seconds and where is it located? or is that the function of the battery saver relay R21? also where are the door/boot light switch locations? i would check the manual but guess what, previous owner lost it!

help and inquiries much appreciated guys!!

2002 X Type 3.0

 

lilblujag, sorry to hear that your kitty has developed a bit of a temper tantrum.

As for your issue with the interior lights. The lights are controlled directly from the GEM (Generic Electronics Control Module) with the GEM grounding the one wire to turn the lights on (they have power all the time). With that being said, the MAP lights and the rear interior light have a switch associated with them that also has a ground wire that is tied directly to the body of the car (this allows the lights to be turned on by the driver at any point).

So, to help you narrow down where the fault is, first, try cycling the buttons for the MAP lights and the rear interior light to see if that causes the lights to change what they are doing (going from dim to full brightness of the one that you are manipulating is expected). If they do, then you have a bad switch and that is allowing the lights to be grounded and remain on when they shouldn't be. Next, check fuse F25 under the hood. This feeds power to the GEM module. Because the lights still turn on and whatnot, this would tell me that the GEM module is still getting power. But, stranger things have happened. Finally, accessing the GEM module in the passenger side rear corner of the engine bay, unplug the connector to the GEM module. Do the lights go out? If yes, then you have a bad GEM module. If no, you have a wiring problem inside the cab of the car.

If you need me to get into more detail, let me know. I will step you through whatever I can. From what I can tell, based on what you are describing, the transient that blew fuse F99 shocked the GEM module pretty good and put an internal fault into it, leading to the interior lights not being able to turn off. Also, having the battery saver not turn off (which is also controlled by the GEM module) is also pointing towards issues with the GEM module.

 

Thermo,

I really appreciate the help and VALUABLE insight in the knowledge background!!! I just woke up about 2 hours ago, and mother earth strikes again, it is snowing once more... dang, i really wanted to play with her today haha... but hopefully it is clear tomorrow, and I will post up the results. Also, I just finished installing a Kenwood KVT-614 to replace the head unit and I was going to install 2 12" Kenwood P-W1200 today but snow has screwed me today. I have my door speakers replaced already with MB Quart ESA 213 component speakers and tweets. The subs came with a free baby amp, Kenwood KAC-5204 so I figured I hook it up to see how it runs the 2 12's... other than that, I just have a set of 20's and 20% tint all the way around. I will set up pics as soon as I get everything installed and cleaned up and let everyone know how it went. Many more plans on upgrades and "pretty-ing" her up in mind. Any recommendations with the audio set up would be openly pondered on haha... But seriously, thanks again Thermo, exactly the direction I was looking for man!!!

 

lilblujag, when it comes to stereos, that is something I have fun with. I have all the components, I just need to install them into my Jag. I have a Rockford Fosgate 5 channel amp (700.5) that I am installing to the factory radio and then installing dual 12's, and separates all the way around. So, should sound good once I am all done. Just haven't taken the time to install it. Hell, even the custom sub boxes are built. I just need to drop the speakers into them. I am going to be pushing right around 700 W RMS inside the car. That should make it thump pretty nicely. Should make it so when someone comes up with a bass car, I will be able to put in some Trace Adkins and show them what a real car should sound like. He he he he he.

Let me know what you need and we'll go from there.

 

Alright sir,

Cycled the rear interior light switch and it did change from dim/bright/off... MAP light will not change with button manipulation. it only dims when i start driving. The left and right reading lights do turn on and off as advertised. So now I guess I have more of a lead right? Now I have to chase wires to find a ground and the bad switch? Or does your diagrams already show where those are found? Fuse F25 is good, not faulty or blown. As far as the GEM module, I cant find it for the life of me. I know it has 5 connections to it right? Now is the "passenger" you are referring to on a NA or EUR model? I checked both sides around the A post, but still dont recognize it, where exactly is it? I have been googling and checking this site for more of location references for the module and have found nothing with significance. BUT I NOTICED THE LIGHT WENT OUT WHILE I WAS TALKING ON THE PHONE FOR A WHILE... so I think the battery saver option might work... I opened the driver door to turn the light back on and shut it about 30 min ago, will post again after another half hour to report weather the shut off feature worked or not.

So, just to put everything together, where can I find the location of the GEM Module, ground for the interior lights, and the switch that controls them, or is the switch literally the switch I touch to turn on the lights and not a switch in a relay? Thanks again for the guidance man, really helps a lot... lookin forward to hearin back from ya...

BTW, the kenwood stereo is GREAT. I havent installed the subs yet because, stupid me, I somehow forgot that the dual ported box I have is made for 2 10's haha, dont know how I mixed/forgot I have 10's and not 12's, so now I have the 12's with no box. But I found a custom box... http://cgi.ebay.com/ebaymotors/Custo...fAudioQ5fVideo ... its on EBay for 125 bucks plus 60 shipping, so no. I know how to build them so I think I will just copy the design and build one myself. And the amp kind of sucked like I thought it would, so I just hooked up a JVC 600 watt amp instead... big difference obviously. But I think the JVC will be adequate to run the 12's... Do you think that if I spliced a fan for the amp, that it would give the alternator problems? I already spliced a multi 3 hole 12v/single USB into the original 12v lighter wires and put it in my glovebox, so I dont want to over power my alternator and have a dead battery or something... what do you think?

As far as Trace Adkins goes, you should play that song Honky Tonk Badonkadonk HAHAHAHAHAHAHA

 

The battery saver option works!!! Woooo hoooooo

 

lilblujag, I think I know where the problem is. What I want you to do is to access the center console in the ceiling of your car (ie, get behind the map lights). You should find a plug that the light assembly plugs into. Unplug that plug. Now, check the lights again. Do they function normally? If what I am thinking is going on, they should. If this is the case, then you have managed to damage the switch on the light assembly and it is now grounding the lights all the time and what is happening is when the GEM module wants the lights on, they see a less restrictive path to ground through the GEM module, so they can then go to full brightness. But, when the GEM module doesn't want the lights, you are running a bunch of lights through the center light switch in the overhead console, hence why they don't light up really bright.

As for the location of the GEM module, if I remember right, if you are standing at the front bumper, you open the hood, look in the far back left corner. You should see 2 black boxes back there. One of those boxes is the GEM module. I will need to look on my car tomorrow to confirm that. If you don't see the two boxes there, then they are hidden under the cowl for the windshield.

 

This website should have the manual.

 

Thermo,

IT WORKED!!! I went ahead and took down the map lights console and unplugged the lights. I put the fuse, F99, back in and checked to see if everything worked, and success! The lights turn off and on like they should, locked the doors, open and closed the doors, played with the switches etc, I just need to take a drive while operating everything to make sure its good, but I'm sure it is. Thank you Thermo so much for everything man!! I guess I don't really need to mess with the GEM module, but I would like to know where it is regardless though.

KDW4Him thanks for the info man haha... it's a really good website

 

https://www.jaguarforums.com/forum/a...p?albumid=2236

Here are the pics I uploaded for the aftermarket stereo...

 

lilblujag, not a problem. I do this sort of thing all the time. Spent the weekend fixing the son's car with a wire that broke in the middle of a run that took out his ignition system. I'm glad I could be of service. Now the trick will be getting a new overhead light assembly. Hopefully that won't set you back too much.