Lighting problems
Q There’s an intermittent fault with the indicators/headlights/ tail-lights in my 1997 Land Rover Defender 300Tdi 110 commercial. When I indicate right, everything works fine, but when I indicate left, the indicators and sidelights/headlights/tail-lights flash in sync. If I turn on the sidelights or headlights, the left indicators also stay illuminated until I turn on the indicator switch, in which case they all flash. If I press the hazard switch, everything flashes in sync. If I just leave the lights and hazards switched on, it varies between flashing/not flashing several times, so I can’t even predict if it’s likely to do it at any particular time.
My first assumption was a bad earth connection or a problem with the switch. I replaced the indicator stalk because it was sloppy and broken inside, plus a previous owner had cut one of the wires (purple) and connected it to one of the headlight switch cables (brown).
I’ve wiggled the relays and cables on the steering column switches, disconnected the sidelights/indicators and the left-hand headlight, but the dash lights still flash in sync with the hazard/left indicator, so the fault is still present in the circuit without any of the lights connected. Short of dismantling things unnecessarily, I’m at a loss. Dave Evans
A As you suspect, the most likely cause of the problem is an earth fault. This could be a poor earth connection between any of the lamps and the body. I would recheck each earth connection to the lamps on the lefthand side and I would also try fitting a temporary earth to each lamp in order to ascertain if this will remedy the problem.
It would also be worth checking the bulbs. As the problem only affects the nearside of the vehicle, I would swap all of the bulbs from side to side. This may have the effect of switching the problem to the other side, in which case it will confirm that a bulb is at fault. If there is no change, at least you will have eliminated the bulbs as a cause.
As the indicator bulb illuminates when the sidelights are on, I wouldn’t think the hazard unit is at fault, but again this can be eliminated by removing the unit and turning on the sidelights. If this prevents the indicator lamp from illuminating, it could be the cause of the problem.