[UKKid35]

My headlights often fail to raise and switch on after the car has been left idle for a few weeks

This inevitably happens when I check the car over just before its annual MOT test

They usually come back to life within a few hours without me actually doing anything, so I've never investigated further

Any suggestions where I should look first?

[Schocki]

If your relay is still original, I would go ahead an replace it. Not cheap but the most common issue with our headlights.

[worf]

If not relay, Ignition switch also leads to wacky light behavior.

Need more details on behavior.

Lights raise but don’t illuminate? Illuminate but don’t raise? Do nothing?

[UKKid35]

Lights raise but don’t illuminate? Illuminate but don’t raise? Do nothing?

Thanks - Do nothing

But eventually raise and switch on if I operate the switch some time later, while the engine is running

[UKKid35]

If I raise the headlights manually using the knob on the motor, they will come on when they reach the correct angle

I can then switch them off and on again using the switch, and they operate correctly

MOT just passed as they didn't embarrass me during the test

[Fox_]

I had the happen, ended up being a weak battery.

[worf]

Relay. Most likely.

[UKKid35]

If your relay is still original, I would go ahead an replace it. Not cheap but the most common issue with our headlights.

It may not be cheap, but I am, so that won't be happening

I might take it apart and spray it with contact cleaner though

[AirtekHVAC]

My car does the same thing, but opposite. New ignition switch, new headlight switch , new relay.

But , after sitting a few days, when I put mine up, they wont go down. After a couple hours of driving, they eventually just go down on their own, and start working properly again. It’s weird, and car is garage kept. Ya know it’s been a couple years since I checked the connector on the motor….

[Fox_]

I had the happen, ended up being a weak battery.

Mine would turn on, but the headlights wouldn't pop up.

Happened after sitting awhile, battery charger or letting it run awhile would fix it.

However, doesn't sound like your issue.