I am posting this for a friend, he recently bought a 99f250 andit does not want to start even when plugged in. i think the block/oil heater is dead, any quick tests to verify?
i tested the glow plug relay and it is good, i also heard that a resistance test from the relay to ground should be around 8 ohms if all the plugs are good, but we only have 0.22, i am guessing that one plug may be shorted and drawing all the power away from the others. it is too cold to be outside with frozen metal for very long so we didnt test each plug (yet). but does my idea sound right, or is there something simple/stupid that i am overlooking? thanks for any advice.