I recently bought a Mitsubishi 1999 Fuso FG, medium duty truck. Does anyone know how do the glow plugs function on this engine? Should they be coming on every time I start it? I don't have an FSM so don't know how to diagnose any problems that might be there. On Mercedes, one bad glow plug will typically cause the glow plug light to go out. Does something similar happen with the FG?
Engine always starts right up, but winter is approaching and I want to make sure I'm prepared.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13