Glow Plug Voltage

[eldomike]

I've read a bunch on this topic but still not sure I understand....I have 12V to the GP relay that drops to about 10v on both relay terminals when the key is turned on....I get a little under 10V at the glow plugs...glow plugs are new Motorcraft and GP relay is new...the wait to start light stays on about 10 seconds the goes off...does not click after it goes off...I would appreciate some input, thanks in advance

 

[DaveBen]

The glow plugs draw a LOT of current and that drops the voltage from the battery. Nothing to worry about if it starts normally. The alternator will recharge the batteries.