I have been doing my homework on the Big 3 upgrade, and cant seem to find info on what I'm looking for so please bare with me, but the ALT to BATT cable, i see what looks like a
sensor. I'm not sure what it is but i could disconnect it if i wanted to. Is that what reads my voltage on the dash/comp and should i re-splice that into the new cable or what? I'm driving an 08 screw 5.4. I know i have to fuse the new cable with an anl fuse. From what i learned, a 200 amp fuse will be good.. Im running a stock amp.

I'd appreciate any other advise.

 

Are you taking out the old batt to alt cable and replacing it? Most people just leave the old cable in place and run the second one alongside it, then you don't have to really worry about messing up the factory wiring.

 

Well i would have like to taken out the old batt to alt cable. I think its pointless having 2 cables, especially if I'm running a 0-gauge cable. But do people leave the old cable and still see good results with it?

 

It wouldn't give bad results, it just means you have even more wire for current to flow through and a fail safe in case one fuse decides to blow, a wire comes loose, etc.

Same with the rest of the wires for the big 3, most just run alongside the old one.

 

Good point. I guess i will do that with the new batt to alt cable. The grounds are pretty much a straight swap so i think i will eliminate the stock grounds. Thanks for the help.

 

Well for the grounds generally the rule is at least match the amount of power wires. Basically if there's current flowing through all the power wires but not enough ground wire for it to get out through your limiting your performance somewhat, will it make a difference for you? Most likely not, but still something to think about.

 

You mean if im gonna run another cable for the batt-alt and leave the factory cable, do the same for grounds? Leave the factory and add on another cable?

 

Yup basically. You can never have too many grounds.

 

Pizzaman, i got another question, i did the upgrade with the 0 gauge wire and all. Now I'm thinking about upgrading the alt itself. My truck is an 08 with 66,000 miles, and when I'm at a light or idling in drive, and if say i have my lights,heat/a.c, radio, or multiple things on, my voltage drops to the 12's... I don't know if i should look into upgrading to a higher output alternator, or maybe my original one is slowly going. Its been doing the voltage drop for a long time now.

 

At times,with basically nothing on, its usually about 14.2v. Then their will be times where it will be at 13.5v with nothing on as well.

 

If your dropping to 12's without the audio really going hard it could definitely be time for a bigger alt. It could also be a sign the battery may be on its way out too depending how old that is.

How bad is the voltage drop now that the big 3 is done? It should've cause some improvement.

 

The batt is not that old. I don't really see much improvement with the big 3. I constantly watch my voltage on my gryphon , and if I'm at a light, dead stop, my rpm's would be around 550-620 and if i have my just my lights and fogs with heat, i think the voltage was around 12.8. I like to see above 14v. Now obviously when the rpm's are low, the alt isn't putting out that much. And my audio system is not a really big system, small amp, pushing 2-12"s(shallow kickers). Now if im driving, moving with my rpms'a above 1000k, i could have everything on and my voltage would be well above 13v, again because of the alt spinning quicker.
A few weeks ago i had a rental and it was a 2013 f150, and i noticed somewhat the same thing. But theirs was no way to monitor the voltage, but i could tell their was a power draw when i accelerated away from a light, the headlights got a little brighter when rpm's went up.

 

your going to be hard pressed to run new 0 gauge wire with the stock wire in place especially at the grounding points on the starter bolt your have 4 wires grouped up their .Rip that stock stuff out .You only need to leave your alt sensing wire stock it has a fusible link in line and is totally separate from the alt to Bat line.Once you unwrap all the stock tape and what not.

 

You totally lost me shanecaseber.

 

The only ground i added was a 0- gauge too was frame to batt and chassis to batt. It is kinda cramped up but i was able to make it fit. And the stock alt to batt cable i left. Didn't wanna mess with what was on that line.