chad,
are you an operator or a technician?
my guess is operator..
checking switches is basic electric 101 stuff

i suggest you call a service tech out if you are not familiar with these things.

where can I find what the fault codes are for my truck?

Can I jump the switch because the 4th spool is not used or jump the switch to see if it is the switch that is the problem. I looked at the 4 switch and it doesn't look to be out of adjustment. The 1st and 2nd spool is for the up/down and tilt. 3rd is for the left/right. I don't think I have ever used the 4th spool for anything.

I bought a service manual on the truck. How can I tell if it is out of adjustment?

chad,
yes there is a service manual on this truck but i'm not at liberty to give that out, sorry.
if you check the switches on the hydraulic control valve on the 3rd and 4th spools you will find one of those most likely out of adjustment, check the last function switch, this is aux2 i believe.

When the truck does its self check on start-up it is detecting a problem with one of those switches probably being closed during the check. If this is the case the truck will not pass the start-up check and code out the code 10 and prevent the truck from starting up.

Is there a repair book out there so that I can see what I'm looking for?

aux2 switch defective
check your hydraulic switches on control valve