Disco 2 '01 D2 Headlight Issue

Morning all!

Odd one for you: when using the headlights, both dipped beam work without issue. When flashing or switching to main beam and back, one dipped beam stops working entirely. (Always the same: passenger side)

This stays off until the trucks been parked for a while, then works again.

Ive read contradictory information where some posts say there is a relay for this which might be sticking, others say this is directly controlled by the BCU and some say it is all in the stalk switch so that needs checking/replacing. Which is correct?!

I note that RAVE shows a pinout on the BCU for headlight dipped and headlight main separately, but does that feed a relay? Surely the BCU isn't supplying and switching that power all on its lonesome?

Cheers,

Hi, the reality is revealed by the circuit diagrams and based on that the headlamps(high and dipped) get feed directly from the stalk through the fuses in the interior fusebox, no relay or other electronics involved, the BCU has to do only with the IP's high beam indication(or DRL which is not UK specific) so your problem is a weak contact which can be in the stak, in the cluster's plug (which is common), that lamp's earth or in the worst case interior fusebox plug or within it, investigation is needed

sierrafery said:

Hi, the reality is revealed by the circuit diagrams and based on that the headlamps(high and dipped) get feed directly from the stalk through the fuses in the interior fusebox, no relay or other electronics involved, the BCU has to do only with the IP's high beam indication(or DRL which is not UK specific) so your problem is a weak contact which can be in the stak, in the cluster's plug (which is common), that lamp's earth or in the worst case interior fusebox plug or within it, investigation is needed

Click to expand...

Thanks Sierra. Ill start by checking the earth on the lamp end, though its odd that it works fine until high beam is switched, suggests the issue is more likely at the stalk end which is mildly upsetting!

Shogun243 said:

Thanks Sierra. Ill start by checking the earth on the lamp end, though its odd that it works fine until high beam is switched, suggests the issue is more likely at the stalk end which is mildly upsetting!

Click to expand...

Hi
I had a similar issue with my D2 a couple of months ago. Replacing the bulb fixed it. I was told by some mechanic that the filaments can join themselves together again within the bulb. I didn't realy believe him at the time, but it may have been true. The problem has not come back again with the new bulb.

I had a similar problem 2 weeks ago and noticed that the plugs that attach to the headlamp globes were burned and black from years of poor quality connection. I replaced the plugs and simultaneously added additional earths on both sides keeping the existing earths as well and that solved the problem.

I had a similar thing on a completely different vehicle, this was an earth wire attached to the front panel. I replaced the bolt, cleaned up the cable connector and all was good.