Peterbilt 579 throwing check engine lights without warnings on dash.

So this one will take a bjt of back info. i just purchased this truck last month. However, it was down for 3 weeks getting a wetkit added (MHC said it woukd take a week heh...yea right) and when i first picked it up it had a full set of shot batterys and badly worn neigh unuseable cables that were so brittle they broke when the batterys were changed inspite of the dealer swearing they put in new batterys before sale. To be fair they did look new when they were swapped so i could be the inspecting guy wiped them down or something. Because of this it kept throwing random errors and eventually gave me an SRC max derate after all of 50 bobtail miles from the dealer.

Got it towed to a diffrent MHC where i found this out about the above and was told the bad batterys sketchy posibly arcing cables and low voltage were likely causeing the 26 odd errors. I then had the codes cleared and new batterys and cables put in. It seemed to fix the problem and the dealer tested it over an hour or so to ensure the SCR fault would not come back.

Now i am about 700 more bobtail miles down the road and just had both yellow lights come on with no warnings on the dash and everything seemingly working fine. Im currently stuck at this hole in the wall doing my reset and waiting until the trailer place opens monday and am wondering if you guys have some idea of common problems to check first before i risk going down the road and blowing another $3000 on tows and repairs before ive even made one red cent with this thing.

I have not idled it more then an hour since i bought it and that was only to function test my new wet kit as well as charge the batterys after all night with a small fan and Cpap running so that should not be the problem? Any help would be apprecated.

 

I figured as much, was just hopeing there were common things to check. I have never used an MX-13 before and im a wee bit spooked after the SCR and battery thing. Especially as a new owner op. Also need to figure out why my inverter is being dumb.