What voltage should the Disco 1 run at? I was going between 11.3 and 12.9, so i got a new Alternator and i'm up to 12.3 to 13.5 now. Shouldn't it be up in the 14 range?
Thanks!

 

seems low. where are you measuring from?

if its the obd2 reader try measuring from the back of the alternator and the alternator case. if theres a difference, more than around .2 volts or so, you got a bad connection or corroded cable. in my experience most likely the body ground attachment or alternator cable


body ground is held on by a 10mm nut between the battery and underhood fuse box.

battery to chassis is by the radiator outlet

engine to chassis ground is by the starter.

 

With the engine running 13.5 would be a bit lower than you’d like to see. Anything less is too expensive low. As said above make sure all your contacts are clean.

 

My mechanic says a battery on the way out draws more from the alternator. This can lead to low voltage, or worse, alternator failure. 13.8 to 14.4 V is typical running voltage for a fully charged battery. 12.6 V is typical resting voltage, fully charged and no load on the battery, that is cable disconnected.