Hello everyone, my real name is Jack and this is my first post!

so a few weeks ago, I picked up a 2003 Discovery Td5. A really nice example in sound mechanical and structural condition.

Anyway, I noticed that the RH side light was not working, so I changed the bulb and no luck. Checked no.33 fuse which also controls the trailer socket and switch illumination as well as the RH side and tail lights but that was good. For some reason, I decided to try the lights without the fuse and, bizarrely, the RH side light came on but of course, everything else that fuse controls did not.

Everything else on the landy works as it should and I’ve replaced the fuse for the time being but has anyone else had this problem or is able to give me some pointers? Has someone possibly messed about with something somewhere or is it just a fault? I’m no electrician but I thought I’d ask here before seeking professional help.

thanks a lot.

Mr bouze said:

I decided to try the lights without the fuse and, bizarrely, the RH side light came on but of course, everything else that fuse controls did not.

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Hi, did iunderstand well ? the RH side light comes on with F33 removed but not with fuse in place ? Check fuse F3 too

sierrafery said:

Hi, did iunderstand well ? the RH side light comes on with F33 removed but not with fuse in place ? Check fuse F3 too

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Yes Correct! F3 fuse all good.

Then it's most likely an earth or wiring issue on that particular side light circuit

sierrafery said:

Then it's most likely an earth or wiring issue on that particular side light circuit

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I thought so. So there could be wires crossed somewhere? I imagine it’s worth tidying up the grounds behind the battery in any case. Are there any others?

Actually, I’ve just remembered that we put the Disco on a trailer and when trying the indicators, it made the trailer brake lights flash instead! Very likely a wiring problem then.

Iffy connections at the trailer socket possibly, that’s where I’d look first and take it appart.

discool said:

Iffy connections at the trailer socket possibly, that’s where I’d look first and take it appart.

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Will have a look tomorrow but I think I’m hopefully getting to root cause. I should’ve mentioned that my disco has two trailer sockets. I’m guessing that’s not standard? Also found a couple of threads on a different site about a trailer plug located behind the RH taillight.