MTS250S Code 802 ??

[Kempy]

Code 802.
I keep getting code 802.
Start machine get 25.9V in Syn. Spool wire set to .035.
Start welding for about two seconds then the spool gun stops.
Machine has code 802 shut off machine restart volts 25.9V or 26.0V weld two or three seconds then it stops again.
Restart machine get 25.9V use selector go through everything back to Syn. Spool now volts is at 23.6V welder work and does not shut off.
Restart machine get 25.9V start welding for about two to five seconds then machine quits welding and code 802.
Restart welder get 25.9V use selector go through everything back to Syn. Spool now volts is at 23.6V change to 25.9 it welds O.K. select any wire size everything work. Shut of welder restart 25.9V any wire size machine welds two or so seconds then quits then I get code 802.