A guide to replacing the branch control distribution unit (the block of black plastic with a number of high amp fuses on top of the battery positive terminal)

This is based on my car, a 2003 Abarth 5dr. I guess most other models will be similar.

WHY BOTHER?

Well, the battery terminals that come as standard are rubbish, thin tin like material, which after a while of tightening and untightening get stretched, bent and distorted.

WHAT STUFF DO I NEED?

A pair of bettery terminals, I used Mutant battery terminals. Linked to here
MT-BTP (Positive) LED Battery Terminal - mutant, mutant battery, terminal, led, voltage - Mutant Shop, speakers subwoofer amplifier - Divine - Powered by WebTail
A pair of AGU Fuse holders (these take any AGU fuse from 20-80AMP. AGU fuses are similar to household plug fuses, little glass cylinders with the visible fuse inside.
Car Audio & Security: Car Stereo, Speakers & Subwoofers, Car DVD Players, GPS and CD Changers
A ANL fuse and holder
Car Audio & Security: Car Stereo, Speakers & Subwoofers, Car DVD Players, GPS and CD Changers
ANL fuses run from 100-500AMPS. They are big units and carry high currents.

Some cable.

I talked to a friendly local ICE installer and got a couple of lengths of quality 4 gauge (Heavy duty/starter motor thickness cable) and some 8 guage, (good for 100AMPs) for £5 in change.

And finally, something to mount it all to. I use a piece of Perspex from a local model shop. Its 5mm thick, and seems to work well

WHAT TOOLS DO I NEED?

A power drill and small drill bits, the necessary tool to remove the battery manacle, and a set of allen keys.

WHAT DO I DO?

1) Remove the battery cover (if you have one)
2) Remove the metal battery manacle bar screws (The thing that holds the battery in) so there is more wiggle room
3) Remove the original battery terminals neg first (Label each cable with the AMP rating needed.)
4) Cut the original screw on terminal ends off, and remove enough insulation to connect to the new fuses/terminal.
5) Connect new cable pieces to the new battery positive terminal, match the new to the old. The starter won't need a fuse, so it just connects directly to the new terminal.
6) Connect new negative teminal and connect old negative cables directly to the new positive terminal. (Good time to add more earth cable if you want to)
7) Now the two terminals are available to connect(don't actually connect to the battery yet!) Place your piece of perspex over the battery, check it for size and shape, should be about the size of the battery. Drill through the perspex and into the battery manacle bar. Now remove the battery manacle bar and drill through the manacle bar.
8) Use at least 2 self tapping screws to mount the perspex to the bar.
9) Refit the bar.
10)Run the cables from the positive battery terminal above the perspex and cut to length. Make sue you have enough cable to connect to the new fuses.
11) Hook all cables up and connect battery terminals.
12) If you used the mutant terminals, hook up the voltmeter wire to ground, then the terminal top voltmeter will work.

Looks like this when all done



SO WHY BOTHER?

On my car, the starter motor now spins faster, the lights seem brighter, and the kangarooing from cold is noticeably reduced.

HOW MUCH?

I bought all my bits of E-Bay. Total cost was £32 exc. postage.

ANYTHING ELSE I NEED TO KNOW?

Be sensible with car electrics, take your time and don't rush the job.

HOW LONG?

Took me maybe an hour all in. But I did solder the ends of the cables to help connections and reduce corrosion later.

Looks good! But would be no good in mine, I need (and like) the origionals as easy to add extra's to, like my DRL's and LPG system coming off of it etc.