01 7.3 glowplug issuse

[caper01]

i have an 01 550 with 7.3 my glowplugs quit working took it to dealer they said that both my glowplug and air intake heater relays were bad. ordered parts replaced both relays tried to start truck and still no start when cold. little shot of ether and truck fires right up. i got power to the one large post but none to the other with key on. i also put test light on both small pins and the test light does not light up when key turned on. i have a code reader and truck throws code p0380 glow plug circ error circ a. my air intake heater relay is acting the same way. any ideas thanks