Ideas on a Pvt. Pyle wiring job?

[bigugh20]

Well riddle me this batman. I had a wire coming up from under the bed, looped over the side and welded to the bed floor. On top of the bed was a crimp on lug bolted down with the wire cut off. An obvious attempt had been made to get an adequate ground for whatever they were trying. Now I trace this ground back and find that it goes through a ckt. bkr mounted behind the battery box and hooked directly to the positive terminal on my battery . The breaker was obviously tripped. Everything seems to be working properly.
Also on a side note I have a resonant vibration that cycles up and down from nothing to a vibration that I can feel in my seat. It cycles at about 1 cycle per second and doesn't change frequency with engine or road speed. It is most prevalent at 48 to 50 mph when everything is smooth.
The wiring I'm not worried about, I simply removed it. The vibration is driving me crazy though.

 

[SoundGuy]

Is there a metal ring crimped on it with a number? That could identify what it is for.
not a clue as to the resonance. I would be interested to find out what it is. Maybe the flasher unit or something. Just trying to think of something that pulses and it not based on engine or speed.

 

[bigugh20]

Is there a metal ring crimped on it with a number? That could identify what it is for.

No, no identification. Based on the method of grounding and the extra butt splice type connectors included, there is no telling what this was an attempt at.