Okay so I think I've figured out my AirDog low pressure issue. My batteries are weak. They are only 750 cca's, and they are three year old Duralasts.
So I'm thinking they can't keep up anymore, especially with the huge voltage needs of my truck (gauges and monitors everywhere, navigation, big stereo, 4 HID's, big 'ole AirDog).
I've narrowed this down because I can use my fuel pressure gauge as a voltage gauge too
When I first crank my truck it's at like 10.9-11.2 volts, and it reads about 60 PSI. Let it idle a little bit, voltage will raise to 13.5-13.8 and pressure goes up to 74 PSI. After driving with accessories and A/C on it will sit about 12.9-13.1 at idle. I'm thinking I need new batteries
So what brand? I was kinda leaning towards Motorcrafts since the originals lasted six and a half years.
What size should I get as well so that I can assure all these accessories get plenty of power??
Oh, and BTW, alternator is a brand new OEM unit.