IF you state your existing tstat IS a RVP(coleman), and you have a blank display, I would bet you have a wiring (power) problem and NOT a bad Tstat. Soime RVP tstats have a on board fuse(glass). Some receive the power(12 volts) from either the furnace or the roof AC. I cannot remember if I ever have had a RVP tstat go "blank" on display that was not power supply related. Of course I only have over 43 years as an RV tech:B On amazon. The LCD Tstat for an RVP is $100. I cannot believe you purchased one for $25. NEVER, unless it was a stolen tstat and then sold on line. Doug
