Hard to Start

[NoBite]

My 2003 F350 PSD has been tough to start the past few months. I have ruled out cold weather. It does not matter if I cycle through several glow plug cycles before turning the key. Batteries just don't have enough cold cranking power. But, once I do get it started (sometimes jumping with another vehicle)and drive a bit, it will start easily on all subsequent events. So, the alternator seems to be fine.

I had the batteries put on a tester. Fine. Alternator, too. Has me stumped. It is almost like something is draining the batteries as the truck sits. I do not drive it daily. Some weeks only on weekend.

What comes to mind that I should have checked?

[icysmooth]

Good question,I really only drive mine on weekends as well,but I have read on here that some guys have had vacuum pumps draining down batteries,etc.
Do you have any accessories added that could put a drain that you know of?

[NoBite]

Bought the only thing that comes to mind is a trailer brake controller. How that could be the culprit is beyond me. If a trailer isn't hooked up, the controller doesn't do anything, to my knowledge.

I checked to see if I had accidentally clicked the dome light to stay on. Negative.

It seems odd to me that if I drive it around, even just 20 miles or so to town, and then shut it down to go into a store. When I come back out, it starts up pronto. Just that first start is a problem, every darn time.