"I checked for voltage at the glow plug relay and found battery voltage of 12.5. When I checked at the glow plugs it only had 10.5v. Is it normal to lose 2 volts in the wires? As well I coated the glow plug threads with anti sieze. Could this be part of the voltage drop?"


The answer is "yes" Volts= pressure amps= volume, what I mean is when the glow
cycle starts amperage are high "volume", volts are less "pressure".
anti-seize applied to glow plug negative side will not effect the voltage.
and it is a good idea to ream out glow plugs holes when installing new ones.