LUVTruck.com

My glow plugs aren't working. I got in my truck to come home after work and it wouldn't start, I was getting fuel out the pipe so traced it back to the plugs. My question is: there are two relays marked glow relay on the passenger fender well. When I turn the key on only one of them clicks.
Also, I checked for voltage when the switch was turned on and I had none at the glow plug. If it matters, The front relay is working and the one closer to the firewall is not. Finally when the key is turned on you hear the relay click on then off within a second, the light in the dash stays on longer. What should the resistance be on a good glow plug?