I'm moving the front starter battery on my SL55 from the engine bay to the trunk. Im using 1/0 30 gauge copper wire, AGM Braille battery, biller mount, and will be installing a second fuse junction in the trunk with 100 amp fuse about 10" from battery.

I'm going to be removing the factory installed positive battery cable and will be running a new one. I found the power distribution block in the front of the car. It's located on the firewall about 1' down on the left side of the engine bay. Inside of the car, it's located in the passenger side footwell area underneath of the carpet and Bose subwoofer.

With the cover removed on the inside, you can see a 250 amp fuse and 100 amp fuse. The 100 amp fuse is for the starter battery in the front and the 250 amp I believe is for the larger auxiliary battery in the rear. (please correct me if I'm wrong)

Instead of running a new cable from inside of the engine bay and through the firewall, it's seems logical to just start the new cable at the source which would be the distribution block in the passenger footwell area inside of the car.

I'm basically trying to avoid having to attach a new cable where the factory cable was removed from which is in the engine bay. This way I don't have to route the new cable through the firewall and all of the cable would be inside the car.

Can I just attach a new cable/lug to my wire and put it on the top post as indicated in the picture? It would be stacked on top of the lug with the red wire that's already on the post which gets routed into a box on the floor. Not sure what this red cable is for? Will I still be utilizing the factory 100 amp fuse in the block and receive charge from the alternator by attaching to this top post that's inside of the car?
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Anyone with a definitive answer here?

 

If you don't know what you're doing then you shouldn't be doing it....applies to many things in life.

 

Why even take the time to write this response. No one knows everything in life and I'm not one to pretend that I do.

What's wrong with trying to learn new things and ask for help when needed? I've been wrenching on my own cars for the last fifteen years and have become very knowledgeable on most things automotive from DIY maintenance and projects.

Are you the type of person to get everyone else to do everything for you because you're afraid of learning/trying new things?

 

The starter is the high current demand device in this picture, there is always some loss in a long run wire so that eats up some of the current. I forget the ampacity of the wire you are using, it can be found with a search. I don't know those cars to advise on the terminal use, and I'm not sure on the cable routing that is used on the trunk mounted battery cars. Just do your home work and don't under rate the cable that will feed the starter with. On those junction boxes you photo'ed, you really need to get the real specs on them, the one terminal you show to connect the main wire to looks like a fairly thin low capacity connection bar on it, if you don't make sure of used amps and the capacity of what your feeding through it can get hot and start a fire. If in that picture those are the stock wire locations, no fat wires go to that terminal you want to use, so I'm lost there. This is one of those need to see it in person before anything is disturbed deals.