I have a couple of questions about the glow plug system. The car starts and drives fine. But sometimes the glow plug dash indicator blinks after start up and it also only stays lit for approximately 2 seconds. I recently tested the glow plugs and they tested fine. I replaced them any way and bench tested the new plugs prior to install. I believe that the glow relay is the culprit but I am not sure. I guess my questions are
1) How long should the dash light stay lit?
2) When the dash light goes out should the plugs still be getting voltage?
3) Is there a test procedure for the plug relay?
4) Would the blinking dash light be an indicator of a bad glow plug relay?

Thanks in advance.