Our 2006 unit is frying the glow plug relay for some reason. 50 amp fuse is fine. I pop in a new relay and test the lead wire before attaching it to the glow plug bus and it has power, then attach the wire and turn the key to heat...it will fry the relay every time...resulting in no power to the lead. Glow plugs work fine when I hook them up directly to the battery. Any ideas? Our service manual doesn't have much about this. Thanks!