Lpg lights

[vinrex7]

I've just bought a car that is fitted with lpg, and inside the car there is a box to switch between petrol and gas. on the box there are 4 lights but only 2 are lighting up. can someone tell me what these lights are? cheers

[chas2008]

i have driven a vehicle with LPG, there was 4 lights to show gas tank level, 3 green 1 red, when the red came on it changed to petrol automaticaly