Stock Wiring Grounding Issue

[ersanalamin]

Anybody can advise me how to fix wiring grounding issues in my galant? When switch turn L or R not only turning lamp blinked but also illumination lamp blinked. When I put reverse gear on, the reverse lamp on and the illumination lamp also shown a weak light. What grounding point i should looking at? A joint ground in engine bay near R headlamp? Or the one in top of speedo?

[Nick Mann]

Rear lights? Or towing electrics?

[ersanalamin]

Rear lights? Or towing electrics?
No. Its reverse lamp on rear lamp cluster. The brake lamp ground point has close spot with head lamp ground point at below lh junction box but no problem with that.