Got a problem. 2001 Excursion Limited 7.3.

Started earlier this year, interior lights would not go out, door switches were OK. Took it to dealership, they said GEM was bad, put new one in (at my expense) and still same problem. Then they figured out push button in front, overhead console light switch was broken and was causing lights to stay on, so disconnected it at my request. Latter, got a used overhead, took light assembly out and replaced, everything worked fine for 3 weeks or so. Now, no interior lights but the running board lights operate normally.
One other thing, don't know if it's related, but the center/third brake light isn't working, no voltage checking with grounding to body and bumper.?? Is this on a different circuit then the other two? Otherwise, everything else works as it should. Thanks for any help, already have over $700 in a broken light switch!

 

not sure why I can't attach any files, so I put them in a dropbox. what I put in there is the interior lighting diagnosis and testing info and related wiring diagrams from the factory service manual. I also added the exterior lighting wiring diagrams and ground distribution. just note, this info was taken from a 2000 manual. it should be the same as your 2001.


https://www.dropbox.com/sh/pa2lyu0vyc7uowr/IaX-9sS1yh

hope this helps
DOE

 

Thanks for the reply! Looks like there could be a number of sources for the problem. Something else, once in a very great while, a bump in the road will cause the interior lights to come on as happened the other night, they worked all the way home, next morning, no interior lights!?
I took the fuse block and GEM out last night, it still looks new and no signs of water damage from a leaking windshield(I have no leak). Switched battery saver and interior light relays, they are functioning. Have power in and out all fuses. Few months ago I took out the aftermarket security system and now I'm wondering if one of the wire taps may have severed a light wire?

 

if there were/are any scotchlocks... under the dash or hood, they should be removed and the wires repaired. these types of fasteners will actually cut through wires over time. they may also be the root of your electrical problems. if the alarm was wired using these types of connectors, you should inspect the wires they were on very closely.

they are the worst possible way to make automotive electrical connections, imho. solder and heatshrink is the absolute best way to go.

DOE

 

Well, my symptom is:

"The interior lamps are
inoperative—both interior and
demand lamps"

So I went to pinpoint K and at K4 (just to be clear, less than 5 omhs is basically continuity, right?) I have no continuity between battery saver pin 5 and interior lamp 3 pin in the box. So it looks like I need a new Central Junction Box, right? I didn't see the exact box number on ebay, but think I would rather have a new one anyway, bet that is going to be pricey!

Since I've got the box out, I went on to K5 and I don't have continuity between BSR pin 1 and C240d pin 1, so there again it says replace the box. Now I did have continuity BSR pin 2 and C240d pin 1. Am I reading this right?

I did go ahead and removed the wire taps and soldered them. I also got a subscription for this truck on Alldatadiy, looks like a lot of good info there too.


Can you tell me what you think? Thanks for the help!

 

do you have a way to scan for codes? and have you gone through pinpoint test "b"?

DOE

 

I might be able to get it scanned tomorrow. I just did the pinpoint b, Have running board lights, no interior, went to B12 and did that check, i have continuity in circuit 53 - calling for a new CJB as well as I understand it.

 

I think I would give the cjb a good looking over before spending any money on one. it sounds like you have a loose connection somewhere.

DOE

 

Sorry DOE, only paid supporting members have that benefit.

https://www.ford-trucks.com/forums/payments.php

Stewart

 

got it thanks. seems odd that I would have to pay to help out other forum members. luckily there are several work arounds that work just fine.

DOE

 

Took the CJB apart last night, all the plates, fuse and relay pins looked like new. Put it back together. Apparently the problem lies elsewhere. Going to be a couple days before I can get back on it again.

 

Had a few minutes before I leave, Did some checking, I have continuity from connector C242a, pin 33, circuit 53 (overhead interior lamp feed) on the back of the fuse block to the connector on the overhead console but no voltage. Have a good ground at the overhead connector as well. So for some reason, I don't have power coming out of the CJB. Fuses and relays are working. Could this be a GEM issue? Thanks!

 

look for power coming from pin 15 on the gem. that one controls your interior light relay. you might also test the function of the interior light relay.

DOE

 

OK, finally got a chance to get back on this. I took the GEM off the CJB and checked for power on pin 15 which I have none. Would that suggest that is my problem? I did have power on pin 16, Ignition Input, so I know my light is good and had a good ground. Earlier I had switched the relays around and also tried a known good one from another vehicle and no lights as well.

Or did I do the check wrong? Should the GEM stay mounted to the CJB and all the connectors be plugged into the GEM, open the cover and check for power on 15 on the GEM circuit board?

Could I open the GEM box and put 12v to pin 15 on the circuit board and see if the lights will work? Thanks for any help!

 

Are your tail lights and dash lights out as well?