Rear mount battery ?

[428street]

I'm in the process of installing the cabling for my rear mounted battery. I checked out the entire process on the website and it looks fairly straight forward. I do have two questions.

1. The directions state to connect the black ground cable with the battery terminal on the end directly to the frame. I assume you have to drill a hole into the frame. I did not see one pre-drilled.

2. There is a black ground cable that came with my set. Not sure were that goes. If you connect the battery ground cable directly to the frame and then ground the engine via the tranny ground strap per the manual what is that second ground cable used for? This cable has two round eye connectors attached to it.

[cobred]

In my trunk I welded a 3/8 bolt to the square tubing and bolted my cable to it.

[SuperHart]

My guess would be to connect the second ground cable from a bolt on the motor or bell housing directly to the chassis frame.

[SSSammy]

You are probably talking about the ground jumper that goes from the firewall, near the circuit breaker, to the engine block. I used one of the threaded holes in the cylinder head. I think it is about 8 to 10 gauge wire. This is for the firewall and instrument panel ground.

At the battery box, my car had a brass 1/4-20 insert pressed into the frame .. near where the shoulder belt bolt holes come through from the cockpit. That's where I put the battery ground lead. Someday, I will drill and tap a bigger hole and put a big lug there, but it works ok for now. And you mentioned the braided ground strap bolted to the frame near the tranny mount. Yes, this strap goes to the tranny housing.

So, we have battery to frame, frame to tranny, tranny to engine, engine to firewall, firewall to wire harness/ignition, etc. Yes, the firewall is riveted to the frame, but the rivets are not intended to be electrically reliable.

Sam

[fkemmerer]

Originally Posted by 428street

I'm in the process of installing the cabling for my rear mounted battery. I checked out the entire process on the website and it looks fairly straight forward. I do have two questions.

1. The directions state to connect the black ground cable with the battery terminal on the end directly to the frame. I assume you have to drill a hole into the frame. I did not see one pre-drilled.

2. There is a black ground cable that came with my set. Not sure were that goes. If you connect the battery ground cable directly to the frame and then ground the engine via the tranny ground strap per the manual what is that second ground cable used for? This cable has two round eye connectors attached to it.

I believe that there are two grounds connected to the engine/transmission on an ERA. The first goes from the transmission to the frame area right below the rear transmission mount. This is a heavy cable, typically 0 gauge. There's also an 8 gauge cable that goes from the firewall to the back of the engine. Best place to attach this is via one of the holes that is drilled and tapped on the back of the passenger side cyclinder head.

- Fred

[428street]

Thanks guys. Answered my questions. I appreciate it.