Headlamps working strangely

[rustbucket]

Fixing my headlights on my T25 which have gone a bit squiffy.

I realise that this may be a very basic problem, I'm just not savvy electrically. I have searched, but I'm still a bit lost.

Both headlights work on normal beam, then when I turn to full beam, only the nearside light works. Plus, the sidelight doesn't work at all on the offside light, even after changing the bulb (although I think this is corrosion on connections, so buying a new part)

Any idea why full beam doesn't work only on my offside light?

Thanks

[rustbucket]

I know that it probably has something to do with the headlamp relay, but want to be certain that this could be the cause before I go tinkering with something I don't understand.

If it is the relay, do I need a new one, or are there other issues I can cross off the list before I buy?

[marlinowner]

Most likely to be the bulb. It has two filaments, one for high beam and one for dipped (normal) beam.

[rustbucket]

I've changed the bulb twice and no change? I suppose it could be two faulty bulbs, but is there any other possibility?

[bigherb]

but is there any other possibility?

Yes the fuse.

[rustbucket]

Changed all broken fuses in glove box and under passenger seat

[CovKid]

Then theres only wiring left.

[rustbucket]

I guessed as much, I've since found out that it can't be the relay if only one isn't working? THanks

[JimmyT25]

Could be the earth crowns under the dash and above the fuse box. A similar thing happened to me and cleaning up and re fitting the earth crowns sorted it.