Alt wiring question?

[Lumpyguy]

Ok so I am getting down to the last bit of my wiring diet for my 818, got a question on the 2 large white wires fron the MFB to the alternator post, I have the MFB under the front hood and instead of buying 8' of large white wires to connect them I was thinking of running the 2 white wires from the MFB to the battery + post and run the 2 white wires from the Alternator post to the starter main post.

It looks like this should work using the big red battery/start cable as my charge cable?

what do you all think?

cheers

[K3LAG]

That will work but you probably want to put a fuse in the connection between the alternator and battery as you will be bypassing the one in the MFB. I used an 80 Amp fuse. I also replaced the two white ones with a single larger red one.

Larry

[billjr212]

what gauge is the single larger red wire you are using? i changed out the 2 white ones from the factory with 2 new white wires and I don't think I'm getting enough charge (2 dead batteries Tuesday - 1 after 30 minute drive to work on the way to lunch and 1 at the last mile of my 30 minute drive home from work). I may have inadvertently switched to a smaller guage wire. Of course, my alternator could also be shot, but that's on the diagnostic list for this weekend.

[TouchStone]

Ok so I am getting down to the last bit of my wiring diet for my 818, got a question on the 2 large white wires fron the MFB to the alternator post, I have the MFB under the front hood and instead of buying 8' of large white wires to connect them I was thinking of running the 2 white wires from the MFB to the battery + post and run the 2 white wires from the Alternator post to the starter main post.

It looks like this should work using the big red battery/start cable as my charge cable?

what do you all think?

cheers

Here is what I did, replacing the 2 wires with a single larger wire:

Alt ------ 80A Fuse ------ Starter ==========Battery + ------- Fuse Box
- 6 AWG
= 4 AWG

[TouchStone]

what gauge is the single larger red wire you are using? i changed out the 2 white ones from the factory with 2 new white wires and I don't think I'm getting enough charge (2 dead batteries Tuesday - 1 after 30 minute drive to work on the way to lunch and 1 at the last mile of my 30 minute drive home from work). I may have inadvertently switched to a smaller guage wire. Of course, my alternator could also be shot, but that's on the diagnostic list for this weekend.

Whats the voltage of your battery while the car is running?

[billjr212]

Whats the voltage of your battery while the car is running?

Also part of this weekend's diagnostic fun. Just want to pick up the wire at lunch today so I'm all lined up for whatever the issue ends up being.

My problem is that I can't work on this particular troubleshooting during the week since my only window to work on the car is after my girls go to bed. Running 818 in the garage at night = crying baby = unhappy wife. :-)

[K3LAG]

I think I used 6 AWG but I don't remember. That was months ago!

I did buy a slightly longer and heavier cable to go from the battery to the starter. I was going to go 2 AWG but I think they were out and I ended up with some nice flexible 0.

Larry

[billjr212]

I think I used 6 AWG but I don't remember. That was months ago!

I did buy a slightly longer and heavier cable to go from the battery to the starter. I was going to go 2 AWG but I think they were out and I ended up with some nice flexible 0.

Larry

Thank you. That is 1 and a half votes for 6 AWG, so I will pick some up.

I reused the Subaru run from the battery to the starter since I have my battery in the back. No problem there even with my smaller battery. Engine has cranked right over and started easily every time (except after the long drives, of course, when I killed it).

[Bob_n_Cincy]

Here is my wiring.
I have my battery in back.
I have 2 fuses mounted on the solenoid hot post.
I run #6 with 60amp fuse to the front battery disconnect then to the MFB 2 white wires.
Bob




wiring.jpg

[Lumpyguy]

Thanks guys, All good ideas, I love this site>