[ReelMagic]

I have a 2003 38 Open and assume the fresh water systems are the same..... My experience shows you should have sufficient pressure in the system with only 1 of the 2 pumps turned on although the second pump minimizes pulsing of water when more than one faucet is in use..... I encountered a similar problem when there is a minor air leak causing a loss of the prime. It was the result of a twisted gasket which is part of the fresh water strainer located to the left of the 2 fresh water pumps..... The rubber gasket twisted somehow when tightened causing a very small air leak,... The system primed with 1 pump on but didn't keep the prime when 2 pumps were turned on.... Suggest you check to ensure rubber gasket is in there correctly..... M2C