I have a 1994 7.3 idi non turbo that has been having issues with the glow plug relay. I checked to make sure all the wires going to the relay were not grounding improperly. This is the second relay that has received issues do to to much power going in. I can't seem to find the issue, I used a multi meter to make sure the right amount of power was going to the relay. When I try to let the glow plugs do their thing it heats up and melts. Any help or ideas would be appreciated.

 

Check all the glow plugs. Sounds like it is pulling too much current. A glow plug may be shorted. You may want to OHM them out.