Does not sound like you cleaned the right ground. if it was easy to get to, it's not the right one. The other ground is in the bottom of the inner left fender. A tough one to see, let alone get to.
Brian
The ground was located in front of the left side battery box down in the bottom. A real fun place to get to. Mine had about 11 wires attached to one stud. After seeing it, it was no wonder I was having ground issues.
Hello,
I have 98 dodge 3500. The left headlight is dim on both beams and I checked the grounds replaced the bulb. It only has one fuse and the right light is bright. Sockets are not corroded but the dim light is 7 tenths of a volt less then the right one measured at the socket. Could the headlight switch be causing the problem? The dimmer switch seems fine.