Scangauge II findings

[schwartzworld]

Just got a Scanguage II. Got it set up for EOT, ECT, Trans temp and volts. First thing I found out was that my thermostat is stuck open, ECT won't go over 177 degrees. That leads me to my next question, which may have to wait until the thermostat is replaced. The temperature difference between the EOT and ECT while warming up is about 10 degrees difference, once the ECT hits 177 the EOT heads to about 185-186, an 8 to 9 degree spread. Seems OK but should assume that this is false due to the bad stat? Also, while driving at 65 mph the temp difference comes down to 5 to 7 degrees if that matters at all. The truck has 95000 miles so it's due for a coolant change. I'm hoping that these numbers are good, stay good with the change and I can buy some time before I'm replacing coolers.

Second thing the Scanguage may be trying to tell me is an electrical problem. The gauge won't come on right away when I start the truck, it takes 3 to 5 minutes to come alive. When it does, the volts are showing less than 12. After about another 3 to 5 minutes the voltage starts to go up to 12.5, 13.2 then 14 or 14.5. Am I looking at an alternator or batteries? It's usually below 20 degrees outside when I've noticed this happening.
Do the glow plugs stay on for a bit after the light on the dashboard goes off? Reason I ask, is that one time when this happened the interior light was on and it was dim. Then it all of sudden it got brighter and the Scangauge came on.

And I didn't forget the most important part: It's a 2005 F350 Dually 4x4 6.0!

Thanks for the help

Fred