Electrical issue after relocating battery to the trunk. Any ideas?

[rugedraw]

I'll try and be as specific as possible.

I used 16' of 2 guage wire to relocate the battery to the trunk. The cable is brand new, and is not pinched or cut into anywhere. The battery is in a battery box in the trunk, the terminals are securely tightened to both battery posts, and I grounded it to a screw I found under the carpet in the trunk on the passenger side.

Up front, the Mustangs have 2 different wires going into the battery terminal: one that goes into the main fuse/relay box under the hood, and the other goes to the alternator. I used a bolt & nut and ran it through both if the open ends of these wires, and tightened it well and taped it up with electrical tape to prevent moisture from getting in there. Basically, it is a bolt going through 3 of these to make the contact:

Of course, they aren't cheap-o ones like this. I used the factory harness and one heavy duty copper one at the end of the 2 gauge wire, and put 1 bolt through all 3.

The issue I have, is that something seems to randomly interrupt the flow of current to my car. The electricity will completely cut off for a split second, and come right back. My radio will go to AM, the time will go to 12:00, and then it goes back to normal.

It does not happen when I hit a bump, or turn hard, or anything like that. I have noticed, that it happens when it is raining.

Any ideas?

 

[akula52]

Power

Well, it is hard to troubleshoot via email, but I would start with your ground. Check the ohms between your neg batt post and you current ground location with it disconnected. If 0 ohms, simulate rain with a garden hose and check it again. I would then check the resistance from each batt post to furhtest termination(i.e. to your bolt connection) and see what the ohns are. Should be 0. I used the factory ground behind the trunk panel on the driver side and have no issues. It sounds like to me you are building a small capacitance with a poor ground??? Good luck

 

[Stangtuner]

Most electrical issues with connectivity have to do with bad grounds.

 

[rugedraw]

Thanks, guys. I'll try the ground in a different spot and see if it helps. I did not know the factory ground was on the driver's side. Obviously, for better weight transfer I want to keep the battery on the passenger side, but I'll try extending the ground cable to the driver's side and see if that helps any.

If anyone has any other ideas/suggestions, feel free to chime in.

 

[kyoshosp2]

I had to drill a 3/8 hole and grind to bare metal on both sides of the hole and then bolted my ground down. then i sprayed it with terminal protector (u know that orange shit in a CAN) to keep it dry. it's mostlikly the ground

 

[SteveP]

def the ground. i had the same problem. re did the ground and no issues. I had a thing mounted to my firewall that i connected the new power wire and the car's wire. worked out good.

 

[joedls]

+1 on the ground. I had the same problem, ground it to bare metal and it worked great.

 

[travelers]

That's it Ground. you need to use a bolt not a screw to hold it to the metal. Moisture protection is good. The bolt holding the 3 wires up front you should spray with either moisture protection or electrical corrosion protection you can get at a good electrical store.

 

[rugedraw]

That's it Ground. you need to use a bolt not a screw to hold it to the metal. Moisture protection is good. The bolt holding the 3 wires up front you should spray with either moisture protection or electrical corrosion protection you can get at a good electrical store.

Well, I did say screw in my OP, but it is a bolt that I used to ground it. It has been raining all day, and I haven't been able to touch it. I also wanted to install my CHE brace with the torque limiters, but I've been able to do nothing of the sort.

Hopefully, I'll get a chance to do both things tomorrow. I'll come back and post my results so the thread can be used for reference if someone searches for this issue.