voltage issues when starting

[lariat06]

2006 ford f250. batteries are about 2 years old. FICM shows 48.5 volts at start up. every time i start the truck up now it drops down around 9-10 volts and will barely start. after a minute or so it goes up to 13-13.5 volts. had the batteries checked today and they are still good. any idea what i can check? connections on the batteries are tight and clean.

 

[DEEZUZ]

The delay in charging is the system waiting for the glow plugs to cycle off before the alternator kicks in.. This sounds like a battery issue

 

[lariat06]

yea it just started a few days ago. before that it would start great with no issues. now it struggles. side note that i should have mentioned my fuel gauge went crazy and i ran it out of fuel. needless to say getting it restarted we drained the batteries. maybe i should have them checked again.

 

[Geralddunbar995]

My truck just started doing the exact same thing. Fuel gauge and all the same symptoms.

 

[DEEZUZ]

FICMs, IC, ECM, all very very finicky when it comes to voltage...

What tests are you running on your batteries? They need to be load tested, and separately

 

[lariat06]

local parts store put a load tester on each battery. going to a different place tomorrow to get them tested tho. Im still thinking battery issue after i typed everything out in the open.