Interior Courtesy Lamps 2000 Expedition 4x4 XLT 5.4L

[ntistnt]

I have seen lots of threads on here and elsewhere about door ajar and courtesy lights staying on and the door ajar light coming on.

Threads indicate usually a dirty latch switch cleaned with WD40 or an Interior lamp relay - relay 1 or a bad fuse.

I have the revers problem. I can turn the lights on from the internal illumination wheel they all come on. As well I can turn the map lights and the rear lift gate light on individually.

My problem is that when I open a door the lights do NOT come on nor do I get a door ajar idiot light. Symptom is the same for ALL doors. Have already checked fuses to insure I have all the correct fuses on both fuse blocks and that they are operational. Also checked the internal; interior lamp relay and it seems to be fine.

I also pulled a latch connector to see if I had power at the latch switch - there isn't any. Should there be power there???

So I am guessing something is disconnected or jumpered somewhere on this old sheriff police cruiser. I am suspecting jumpered out and disconnected otherwise I suspect I would be seeing door ajar messages and the lights would be on. As well I suspect if it was a pinched wire somewhere I would be blowing a fuse which is not the case. It has been this way since we got it from Fresno County Sheriff Auction.

Just wondering if anybody might have an idea where to check. Not sure where the overall main door wiring harness plugs into. Any other diagnostic tests I can do to test anything out further without destroying something or damaging something else.

Thanks,

Norm

 

[Interceptor]

Hi Norm, good to have you on the forum. I guess one of the first things I would look at is the GEM (General Electronics Module). The GEM is the device which handles control of things like door ajar, etc. I think General Motors products equivalent is the BCM (Body Control Module).

My thoughts are that you're on the right track - somewhere there might be a jumper to make the GEM think doors are closed. The boys in blue don't like dome lights coming on when your open and closing the door.

I believe the GEM is in the area of the fuse box, so maybe go looking around that area for some suspicious wiring changes, etc. I'm sure someone else will come along to this thread that has other ideas.

 

[ntistnt]

Gem - ?

Many thanks that is a great lead. Now I just need to have a better idea of what I am actually looking for and its location.

 

[Interceptor]

If memory serves me correctly on the 2000, the GEM is mounted on top of the interior fusebox. There is not really anything that you can service on the GEM itself, but I'm thinking there might be some obvious modifications made to the wiring harness in the area - look for cut/spliced cables.

I would not suggest taking any action, just look around and see what you might find. Attached is a picture of the typical GEM from that year/model.

 

[Interceptor]

Two more leads that I ran across.. there is such a thing called "dark car" mode on Expedition SSV's (special service vehicles). It's quite possible the newer models have this as a "programmable option" in the GEM. In other words, you may need someone at the dealership to "disable" this option. This is speculation based on some research I did, not 100% sure.

Another tidbit that I came across .. but this is applicable for the good old crown vic interceptors. It's called "dark car" mode. There is a plug you can pull which will turn-on "dark car" - everything works the way yours does.. or plug it back in for normal operation.

I have absolutely no information on the Expedition Special Service package, so I don't know where (or if) this blue plug exists on that model.


Thought it might be another good lead. Check out this link:

http://www.p71owners.com/showthread.php/23-Police-quot-Dark-Car-quot-Mode

 

[ntistnt]

GEM Still Searching

I looked last night for the GEM but don't think I have found it yet. Did not appear to be a black box sitting ont he backside of the fuse panel.

I will look again as there was a boxy thing there but did not have wires going into/out of it.

Other spots I have heard of for its location are behind the stereo, steering wheel column, or to the left rear of the steering wheel column.

Also will look for the dark car mode jumper wire you mentioned in the other post.

So far these are the best leads I have heard of thanks for the tip.