This may sound stupid, but......where can I get a schematic,diagram of your typical lay-out for my car wash (self serve). It kind of looks like the previous owner may have done away with the separate engine cleaner (chemical) and uses the tire cleaner for both. Which means that I have more solenoids, hoses, & connections than I need. I don't know, but it would seem easier to have a jumper wire on the switch for the same system, right. Where all should I have check valves. Please keep in mind I am completely new to this business, but can be easily taught. Thank you!