If it worked before lengthening the wires and it does not work now, you will probably still have a problem after adding a relay. Unless you re-wire everything associated with the purge solenoid. Did you use butt connectors, taps or solder? Did you strip off enough insulation if you used butt connectors? If you used taps, was it the correct size to penetrate the insulation and make contact with the wire? Run a wire from the battery to the wire on the switch the supplies power to the purge. If the purge does not pick up, then you have a problem with the wire to the purge. I'm assuming that when you tested your purge directly off the battery with a wire, you connected the +12 to one side of the purge solenoid and left the other wire from the purge to the existing ground. If so, then your ground wire for the purge is fine. If it does pick up, then there is a problem with the wire going to the switch. Poor connection or possibly a melted fuse that will not let enough current to pass to activate the purge. If you want to have a relay purge system that is ground activated through a switch, then you need to have +12 going to the ? On your diagram instead of the ground. As stated above by boostit. Personally, I would not want to wire it that way, being a switched ground for the relay. If you mount the relay under the hood and run the switched relay through the fire wall to the switch, there is a chance that the ground wire insulation could chaff and make contact with the vehicle, which is ground. There would be no way of shutting the purge off, other than pulling the +12 wire off the purge or relay. If your bottle was closed, you would not even know the purge solenoid was picked and it would eventually burn up. You need to have a +12Volt arm switch for all your solenoids. And quite possibly a master arm switch. The master would supply power to the arm switch, for your spray solenoid(s), and the master would supply power to the purge, bottle heater and remote bottle opener. If it was me, I would at least keep the ? on your diagram a ground as you have it and have +12 go to your purge switch. The +12 going to the switch would need to be fused as well. Yes! You are making it more complicated than what it is. Lol.

 

It works! Pulled out the wire running into the firewall and it looked like there was a spot the wire was burned. Weird...IDK how it was transmitting power with it being burned. Oh well.

I just learned a thing or two about wiring though lol. Thanks for your help!