I'm having a terrible time trying to figure this one out. My Alt gage sits just below half (D side) when my car is on and driving. If I hit the brakes, put my turn signal on, wipers, etc... the gage will drop even further into the D side. When I put my running lights on it will drop about half way down the D... headlight bring it almost all the way down. Ive added more grounds, cleaned connectors, and searched for shot wires.I cant find it and I don't know where else to look. New alt, good batt, new volt reg.

 

Unless you get a tester and probe all the wires to find the problem, you'll need to call an auto electric shop and have them find it.