Trunk light quit working

[TexasRebel]

A few days ago I noticed my trunk lamp would turn on when I began to open the trunk lid, and then turn off as the lid was fully opened.

Now it doesn't even seem to come on at all.

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[Jackson1320]

What is your question, concern, point?

 

[TexasRebel]

What would cause it to cut out in such a manner?

It doesn't seem to be burnt out. I've prodded around for the switch a little in the dark, but haven't found it. I'm not sure if the switch is in the latch or the catch.

 

[ORRadtech]

What year is the car? The first couple of years had issues with the wire bundle from the body to the trunk lid breaking wires.

 

[TexasRebel]

What year is the car? The first couple of years had issues with the wire bundle from the body to the trunk lid breaking wires.

2016 - Car in profile.

I guess that could be it. I'll check if the trunk ajar lamp comes on.
The camera has been flickering a little lately, too.

What's the repair for that?

 

[ORRadtech]

What's the repair for that?

Find the broken wires an fix the breaks...

Do a search on the forums, it's not an unusual problem.

 

[BMAGOO]

Check your fuse also.

 

[Cobra Jet]

If it's not a bad bulb, loose bulb or fuse issue, check the harness that is on the right side (passenger) of the trunk lid when you open it. That harness is known for causing a variety of electrical issues.

Here's some threads that will help. Harness location and fixes: https://www.mustang6g.com/forums/th...op-working-heres-the-fix.117245/#post-2465359

https://www.mustang6g.com/forums/th...op-working-heres-the-fix.117245/#post-2465359

Trunk lid specific:
https://www.mustang6g.com/forums/threads/2015-mustang-gt-trunk-latch-will-not-open.103386/

---
If you're having issues with the rear taillights:

Post #25 of this thread:
https://www.mustang6g.com/forums/threads/tail-light-out-then-back-on.101551/page-2

 

[TexasRebel]

I was able to get it to flicker a bit by playing with the harness near that zip-tie rivet.

Seems like that bend is starting to give out. (bad design--concentrated stress point in the harness)

There is no chaffing or outward damage. I haven't undone the harness yet because I didn't have the supplies (heat shrink) to rebuild it.

 

[TexasRebel]

Changed the harness out. Found a couple of the wires were completely severed, and others were hanging on by a strand. Of course, now my reverse camera isn't working... Hopefully it's just because I didn't connect the shielding. I'm going to try a jumper connection around the Deutsch connector I added.

 

[TexasRebel]

Yep. Even though the new harness doesn't include a pigtail for the shield to connect, it is necessary to keep noise out of the video signal wires.

 

[Cobra Jet]

Yea, that rear trunk harness has been a problem on the S550 since inception and seems to be more of an issue with the 2015-2017’s, haven’t heard many complaints with the 2018+.

I had a prior 1995 BMW M3 (E36) years ago and all the 3-Series E36’s from 1992-99, had the same issue with the trunk harness being damaged from use. In some instances it was a fire hazard and IIRC, it may have been a recall at one point.

Not sure why the Ford harness isn’t a fire hazard - maybe not enough complaints to the NHTSA.

 

[TexasRebel]

Yea, that rear trunk harness has been a problem on the S550 since inception and seems to be more of an issue with the 2015-2017’s, haven’t heard many complaints with the 2018+.

I had a prior 1995 BMW M3 (E36) years ago and all the 3-Series E36’s from 1992-99, had the same issue with the trunk harness being damaged from use. In some instances it was a fire hazard and IIRC, it may have been a recall at one point.

Not sure why the Ford harness isn’t a fire hazard - maybe not enough complaints to the NHTSA.

I imagine because there isn't much current available. The biggest draw on the coupe would be the camera, but that cannot be powered with the vehicle off, and when it is powered, it's probably only on as needed.

The rest of the harness is grounding switches. Doubtfully capable of anything higher than miliamp draw.

Convertibles have a brake lamp and antenna connection. The brake lamp is probably the biggest threat for a fire hazard (not to mention the obvious hazard if your third brake lamp is out).

 

[Motorcycle Rebba]

S550 community,

Have a quick question related to the trunk light. I have a 2017 GT and noticed recently (after the dealership performed the wiring harness recall for the rearview camera) that when the car is locked and I open the trunk with the trunk release button (right above the license plate), the trunk light does not illuminate. Is this normal? If someone (preferably with a 15-17) wouldn't mind checking this for me. Once I hit unlock on my fob the light does come on, so the bulb is not the issue. Can't remember if this is normal and would appreciate if someone can try this and respond back. Car locked, trunk button above the license plate, does the trunk light illuminate?
Thank you in advance.

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