Battery Cable Routing

[karlos]

Happy Memorial Day, all.

Trying to route my battery cables without the benefit of having the engine (small block Ford) in the chassis. My routing will be similar to the photo shown below, which I believe is from one of Edwardb's build threads. The photo's a bit dark, but as near as I can tell the cable for the starter appears to break out of the loom a couple inches forward of the point where the diagonal for the transmission tunnel joins the main chassis tube. Also would like to know what the length of the cable is from where it breaks out of the loom to the lug that attaches to the starter. Guessing about 8 inches.

Thanks in advance!

-Karl

[edwardb]

Yep, that's my #7750 Mk4. Sorry about the dark picture. I had trouble getting good pics with the gloss black powder coat. I just went out in the garage and measured on the car. Your guesses were pretty good. The cables exit the harness 2 inches in front of the diagonal to 4-inch tube joint, and are 8 inches long from the exit to the center of the terminals. The length dimension isn't super critical. I have a little bit of curve in the cables. The curve could be increased or decreased as needed. Note this is for a 302 sized SBF (DART) and a stock type PGMR (Bosch) starter. I obviously have no way to know how these same dimensions would work with other block or starter combinations. Hope this helps.

[karlos]

Yes, this was a big help. Thanks Paul. Really appreciate you taking the time and effort to take a measurement.

Used your dimensions as a start point and tweaked things a bit based on the particulars of my setup. Doesn't look much different as you can see below. One thing I did do differently was to put a MegaFuse for the alternator in the engine compartment, mounted to the passenger side motor mount (second photo). One side of the fuse goes to the alternator; the other goes to the battery side of the master disconnect switch (8GA wire on the bottom terminal of the switch, 3rd photo). This results in a direct connection between the battery and the alternator which should protect the ECU from transients when the switch is thrown, and will meet NHRA regulations that specify the engine should stop when the switch is open.

[edwardb]

Looking good. I did a megafuse on the alternator as well, just in a different location. Nice work.

[DanC]

My MK IV battery is located in FFR stock location in the trunk. FFR sent a 12" battery cable. I'm intallinbg a SBF engine. What is the battery cable length needed? I'm routing down the passenger side of the tunnel.