While at Bluebonnet Ridge RV Park in Terrell over the holidays, I picked up a card for a mobile tech. I saw this tech out at the park two different days we were there, and these were full-timers using them. I cannot personally recommend them, but might be worth a shot.
Canton Rv Service & Repair
14426 Fm 859,
Canton, TX 75103
(903) 567-5563