98 2500 6.5 td with dual batteries. Both batteries test good individually.
Cant get more then 13 volts on volt gauge fully charged running. Cleaned all posts and still only 13 volts. Consequently my headlights are p*ss yellow. Swapped over the highbeams over to Sylvania ultra blue .....better!.... but still very dull. Alternator replaced with an oem replacement 1.5 years ago.
Any help?
Volt gauge in dash can read whatever you want, the needles can be pried off and put on in a different 'clock' position.
Verify voltage at the alternator, from charge stud to alternator case.
As far as headlights go, these trucks typically have ~11.2V at the headlight terminals, to fix, disable the DRL's and install relays and larger wire to the lamps. Simply pulling the fuse will disable them.
Read the chart:
http://www.danielsternlighting.com/tech/relays/relays.html
Ultra blue lights are junk.
http://www.danielsternlighting.com/tech/bulbs/blue/good/good.html
If you truly want to 'see' in the dark, you need full voltage at the bulbs and good ( new ) OEM housings, HIR 9011 / 9012 bulbs (
not HID, HIR stands for Halogen Infared Reflecting )
Yes, the OEM headlight pricing will suck. Most aftermarket housings are junk, pure unadulterated junk. Bunk adjusters, light radiation patterns that are not legal conforming or safe for oncoming traffic.
If your budget is tight, clean the lenses ( polish ), disable DRL's and install relays, larger wire and plugs. Even with 'old bulbs' it will give you a lot more light on the road.
Once you can afford it, buy GM ( Vosla ) bulbs for the housings. 9011 and 9012 to install in place of the 9005 and 9006. They are electrically and optically compatible with the housings.
The key on the bulbs will require very slight modification to install in 9005 / 9006 positions. There are many tutorials on the internet on how to do this.