Compressor help!

[jmag86]

Hey guys, I got in my truck yesterday and flipped my toggle switch on to kick the compressors on and I got nothing......can anyone lead me in the direction of where the promblem might lie? I checked the switch its giving power to the relay and I highly doubt that both compressor gave out at the same time, could it be my pressure switch that's bad?? I have a 5 gallon tank with 8 1/2 asco valves, dual dc 7500 compressors and a stinger 200 amp relay......why such a big relay I don't know that's what the shop I took it to put on it. So any help? Thank you guys once again!