Engine won't start, what to check first before getting services of mechanic?

Good day sirs. Someone might be able to help. Vehicle is a gen 1 pajero (4d56 n/a).

Situation: engine didn't start today. Things I observed to be out of the ordinary are: indication lamps for the glow plug/heater, fuel/water separator & battery does not light up when ignition key is turned on. Hazard, turn signals, door ajar, radio & lights, however, are ok. Nagamit ko pa kagabi. Ok naman.

Checked fuses, all are ok. Will have to contact an electrician, but just wanted to know if there is something else I should check first?

Thanks for any advise.