2004 Tahoe Wiringg Problem---STILL not Located

[rwag1945]

I have had several folks try to help, but the problem still exists on my Tahoe. I found a melted/missing prong on my connector, which I have replaced. Also the 7-4 adapter, 4 wire pigtail and trailer harness are all new. All circuits test properly at the connector...until the trailer is plugged in and then everything goes haywire. The trailer has a good ground, and I have pulled all of the grounds in the rear of the Chavy wiring harness and cleaned them. The Tahoe lights work fine and there are no fuse problems. The only item I cannot test is a small box located near the Tahoe right tail light. When it is unplugged, there are about 15-20 prongs, all clean and in good shape. Is this some sort of solid state module that could have been damaged when the connector prong melted?
Anyone who can solve this gets a BIG kudo!
Thanks,
Ron

[unplugged]

Do you have the same problem with other trailers or just this one?

[ahmitchell1]

I was going to say the same thing try another trailer

[rwag1945]

Yes..I have a boat trailer that does the exact same thing. They have worked fine since 2004, now both have problems. I'm sure it's not the trailers. Thanks.