My first post here. I’m stumped. I’m working on my son’s 2003 GT. 4.6 5 speed T50D. The reverse lights are on whenever the key switch is on. I assumed the back up light switch was bad so I replaced it. The first time I cranked it up they worked perfectly. However, from that point on they stay on all the time. Doesn’t matter in any gear or neutral. The switch came with a new pigtail connector exactly like the old one. The wiring that I can see looks fine. Any ideas anyone? Thanks!

 

They are on even with the switch unplugged

 

Replaced the gem module and no joy. They still come on with the fuse pulled! To clarify they do
go out when the ignition switch is off.

 

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Thanks for the reply. I unpullged the connector on the gem module that contains the bk/pk power wire to the reverse lights and the still are on whenever the switch is on.😞

 

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I think it’s fixed. I was thinking a short to hot would blow a fuse. Maybe it was a ground problem and back feeding. I cleaned all the grounds and it works properly! I suspect it was the ground under the dash to the right of the center console. That was the only place I saw any corrosion. The bare metal dash had some slight surface rust.

 

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So, it was not fixed. I also had a misfire that wouldn’t trip a cel under acceleration in high gear. I replaced the leaking intake, plugs and several coils. I did find the problem and it’s working perfectly now. Rodents had chewed the wiring harness in the right kick panel behind the glove box going to the pcm. The wires were repaired and the misfire and reverse light problem were both fixed!

 

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