Regulator on gas grill freezing

Anyone run into this issue??? 09 Integra I plumbed into coach propane line for gas grill and now regulator is freezing up shutting off the grill. 1st I plumbed into to regulated line off the tank and being it was going through 2 regulators it had a weak flame. Now I plumbed into the line before going into the reg. on the tank and only going through the reg on the grill. Now it freezes it up. Any suggestions appreciated