Land Rover headlamp wiring issue. Any auto sparks around?

I have a strange wiring issue on my 300 Tdi Discovery.

The left hand side headlamp is dimly illuminated even when the the light switch on the steering column is switched off. The right hand side has a slightly dodgy connector which I need to sort too.

I can’t figure out how power could reach the bulb without going through the switch.

Can anyone point me in a productive direction?

Are the side lights off?

I whipped out the whole headlamp units to check the connectors, I noticed that the side lamp bulbs were a bit silvered but they weren’t illuminated. The bulb that was illuminated was the dipped headlamp bulb.

The switch only switches a relay, no ? I’d be checking that the relay is working as it should.

Other than that advice, I can recommend the LRO.com forum for being useful/helpfull.

I will get the manual out and have a look for the relay location.

I think it’s in the passenger footwell.

Suspect a little time with wiring diagram and a multimeter will probably be required.

As it’s a Landrover the wiring diagram is at best, aspirational rather than descriptive. Have you checked the switch for shorts? Other than that it’s out with the AVO and check wires. Not a sparks, just a Solihull sufferer. I need to sort out my indicator and reversing light next.

Remember, Faraday invented the circuit, Lucas invented the short-circuit.

Best bet would be to clean up bulb holders and connectors check condition of earth points in the wings. Maybe take the side light bulb out and see if that turns the dipped beam off. Had a few where the earth point has been coroded and since its shared between all the lights in that wing it will just light up whatever it feels like at the time.

If the relay is in the passenger footwell that may well be the problem. We had a lot of rain last night and there was water lying on the passenger side rubber mat.

Previous experience with LR wiring was limited to my IIA. It was about as primitive as wiring could be.

Hit everything with a hammer till it starts working 🙂

stock up on some of this in case you need it when poking around with the wiring…

I need some of that for my Aprilia!

Think quite a few of these end up modified to cure this, relay fed directly from the battery and use the original wiring to drive the relays only.

I sorted out the connector on right headlamp and it too won’t go out.

I want to eliminate the relay first but I can’t find a reference to it’s location in either the Haynes manual or the handbook. I can only see one relay under the steering column, on the passengers side there is just the heater motor.

P – is this any use?

Do you have a “passenger compartment fuse box”?

Cheers Stoner, I had a look under there but all I could see was the heater motor. I will have another look.

Had another look and can’t see owt like that. Bummer.

Feels defeated.

Take Parkesie’s advice and check the earths, dodgy earths are a frequent cause of odd symptoms like that and as he says, almost anything can light up through reverse feeding and all sorts.

There’s actually no point in trying anything until you’ve re-made the earths.

What year is the car? Does it have a body computer? Lights staying on or glowing dimly can be a symptom of a failed computer.

Take Parkesie’s advice and check the earths

I rerouted the wing mounted earths to something more solid.

What year is the car?

Old school ’95 300tdi Discovery.

The fuse box might be under the steering wheel – with a couple of big plastic screws holding it in place ( at least according to Mr Google ).

The fuse box might be under the steering wheel – with a couple of big plastic screws holding it in place

Yes, that’s where I found it, but there was only one relay attached to it that I think was the indicator relay.

Where does your manual show the headlight wire coming from, and the switch wire going to, if there’s no relay.

’95 Disco is a bit upmarket for me, I’m more familiar with the older stuff, but I know many modern trucks and buses don’t use relays, or even fuses, for the headlights, it’s all done by the ECU.

Where does your manual show the headlight wire coming from, and the switch wire going to, if there’s no relay.

I will need to scan the manual page as I’m pretty useless at reading wiring diagrams. 😳

I’m pretty useless at reading wiring diagrams

Oh dear. Perhaps not the ideal qualification for owning a 20 year old Land Rover. 😕

I posted this over on landyzone too. Turns out it was a dodgy resistor that sits behind the screen wash bottle. I disconnected it and all is well, lights back to normal.