Join Date: Jul 2007
Feedback Score: 0 reviews
Yes, I read it, but you are misunderstanding what you are seeing. The amp load when starting a 6.0 and while the GPs are lit, which is for several minutes after starting, is extremely high. It is too high for a stock output alternator to fill the void created by the drawdown of the batteries. So what you are seeing is the load draw the batteries down to a degree for which the alternator cannot compensate. Once the GPs go out the alternator can fully recharge the batteries, which is why you see the reading go back up. A weak battery exacerbates this effect.
This is why 6.0s seem to go through batteries much faster than other vehicles. My stock batteries lasted all of two years. I then switched to Interstate Megatron II batteries from which I typically get 5 years. My stock alternator has 194k on it and still does the job.
An option is to swap in a higher output alternator like one from DC Power, but they are spendy ($300+).
Still another option is to upgrade the charging cabling from that alternator by adding a 1 gauge wire from the charging post to the + terminal on the RH battery, and add a 1 gauge ground from the alternator case to the chassis ground lug on the crossmember. I did that upgrade about 74k ago.
'06 F250 4x4 - 5" Flo Pro exhaust, SB Filter intake, Accufab elbow, Edge Evolution (monitoring only), SCT w/ ID custom tune, FASS 195 pump, Gillette Diesel EGR cooler delete, Sinister Diesel coolant filter, ELC coolant, updated turbo drain tube/oil feed line/STC fitting/oil cooler, ARPs w/OEM HGs, Elite coolant lines, ITP RR fuel system, RCD 175/30 injectors, Powermax, BD CCV, FICM.com FICM w/ ID tune, Elite UP, BPD water pump - 13.069 @ 101.94
'02 WRX - Outback rear disc swap, EBC green pads, DBA pillar vane rotors, TXS UP/TBE/TMIC, Perrin LW crank pulley, PPG billet steel shift forks, ACT Streetlite flywheel & clutch, K&N filter, STi Group N motor/trans mounts, TiC/Kartboy rear diff mounts/subframe lock bolts/outrigger stiffeners, Kartboy SS & all shifter bushings, custom PDX tune for Cobb AP - went 14.1 on a terrible 60ft before most of these mods; shooting for 13.50s