ive relocated my battery to the trunk a while back but no wthat im in a colder state i think that im having ground issues. Can someone tell me what i need to do to fix the problem. I also have door poppers installed since it started getting cold, they have been acting up. the shop grounded them to the doors but im gonna run the grounds to the body of the car and see if that helps. I have a 0 guage power wire going from a optima battery to the hood and a 0 guage (short) ground wire in the trunk. i was thinking of running an additional ground up to the hood to see if that helps. Also is there a smaller battery that can fit up front to where i can have two batteries in the car.
taking voltage drop measurements with a dmm will help you to locate low resistance electrical paths. here's how to do it.
with your dmm set to volt's dc measure from your battery post to where you would like to make your ground connection with your battery under load. for instance you want to acquire a better ground for your door poppers. while activating your door poppers (battery would now be under load) measure the voltage drop from negative battery post to the ground lead/terminal on the popper. the ideal would be o volts dc but you'll never see that. however if you see 1 volt dropped you have some serious resistance and need to reground. you can also do likewise with the +12 side of the circuit. measure from the pos battery post to the pos lead/terminal on your door poppers and again you should be looking for a low voltage drop.
if you find a large voltage drop do this, with your meter still connected to battery post and battery under load use the other meter lead to probe surrounding metal to find lowest voltage drop and make ground connection at that point where practical and within reason. scrap metal bare and use a star washer to bite in and ensure good bond.
hope that helps