I recently bought my first truck. It is a 2003 Int'l 4300 straight truck with a Dt466, air brakes and suspension. I have a few questions about it. First there is no switch inside the cab that I see for dumping the air in the air springs. How do I do that?
don't do it.....
if there aren't any dump valves, it was built that way..........
Secondly, I see that I have two fault codes that display on the dash. How do I figure out what they indicate?
simple.....you need a mechanics reapir manual. you should check out all the owner's manuals that came with the truck. you can order a "mechanics repair manual", NOT A GENERIC at a parts store.....but, expect to pay over $100 for the manual. then, the fault codes "might" be in that manual, otherwise, you'd nee to buy yet another "mechanics manual" specific to fault codes. again, price's are high.
Third, and finally, being in Minnesota I have to plug it in at night most of the year. Last week it was minus 15 when I went to start it. It didn't start even though the tanks were full and it was plugged in. How/where do I check to make sure the heater(s) are working? Is it a block heater or ?
the "block heater" as YOU CALLED it, is probably working, but then too you need to realize that the engine (for best results) should have just been shut down after a long day of work. the "block heater" usually maintains the temp from there. if foe instance, the truck was sitting for a day, never used, and then you plug in the heater, it'll take a very long time for it to reach the temperature needed to keep things warm. these devices don't always last long by the way.
your fuel is cold too, sitting out there. you might be in serious need of tank heaters as well. you said "once it was in the shop and warmed up, it started"....there you go, cold fuel, maybe even slighlty gelled.
use Howe's diesel fuel products.