Yes it does sound like an open ground. I will always add as many grounds as possable to everything. Like three from the engine, one from the battery to the head, one from the altanator to the frame and one from the head to firewall, All 6 ga except the battery is a 4 ga. I also add a 10 ga from the battery to the firewall. Under the dash I add two 10 ga grounds strapped from the firewall to the Dash frame.