I started having some weirdness a while back, and it turned out the fuses were not blown, but that there was so much oxidation built up between the fuse and the fuse receptacle no current was passing. Rather aggressive cleaning was needed, 400 grit sandpaper on a q tip.
The Ciggy plugs are also prone to such oxidation, where the ground prongs cannot make contact with teh inner body of the receptacle.
Ciggy plugs and receptacles are very poor electrical connections. I refuse to have them pass more than 60 watts continuous these days.
If you are running higher wattage items via a ciggy plug, problems will happen, its just a matter of time.
but it is an ubiquitous connection, convenient. When I have to use one I make sure it is fed 10 or 12awg wire directly from the battery, fused at the battery.
More voltage reaching devices makes them work better, more efficiently, as there is less loss of wattage as heat inside the wiring and or connector.
Some Small 120 and 150 watt inverters will come with a ciggy plug. If actually asked for 150 watts through a ciggy plug, things will not go well. Always best to hook inverters close to the battery over fat copper wires.