Tripack problems

So after Edmonton, i ran down to Calgary and shut down for the night. I got up next morning and flicked the kettle on, and as usual, the tripack came straight on. Then after about a minute it stopped, unusual. So i looks at the controller and the apu ( auxillary power unit ) light is red and the display says ALT, anyway the kettle boiled, i made my cuppa, turned off the controller, turned it back on and the same thing happened again. So i figure ALT means there's something wrong with the alternater and fired up the truck. I ran round to the yard and went in to the workshop. After a bit of digging about, the guy in the shop found some corroded wires coming from the alternater and managed to do a temporary repair. While i was waiting, i got it booked in for the upgrade to be done while i'm off in may. So the repair was done and a few other little jobs aswell. I pulled the truck out of the shop and parked up. 2 minutes later the tripack stopped working again! AAAAAGH!!! So i gave up on it, i only had another day to do, then i had 3 days off booked, so i said stuff it i'll go home early, and let the Lethbridge shop have 4 days to play with the damn thing. So i rang in and got a trailer straight back, cleared the truck and went home.