Headlight delay

[solihulladi]

So I have another odd question for you guys.

I’m having a bizarre issue with my headlights. When I start the car from cold only the sidelights will come on, as I sit there and the car starts to warm I hear a clicking from the relay which gets quicker and quicker and then the headlights come on. When the car is warm they come on straight away.

I’ve replaced the relay with a new one but it hasn’t made any difference.

The time between starting the car and them eventually coming on is getting longer and longer which is concerning me.




Any ideas what could be causing this?

[Doctordiesel77]

That is a weird one, not seen it before, but sounds like the relay is not getting a high enough voltage at first. I wouldn't likē to bet on which connection is bad, but it would probably be worth checking all of your earth connections, starting with the battery/engine/chassis one. Might be worth checking the battery voltage at cold start too. If none of this throws any clues up, then bad connectionß on th live side my be to blame, possibly in the fusebox area. Does everything else work as it should and no suspiciously dim dashboard lights etc?

[Jeff Turbo]

Could also be the connections on the switch, vibration could be connecting it. Worth removing, cleaning and putting back on

[solihulladi]

That is a weird one, not seen it before, but sounds like the relay is not getting a high enough voltage at first. I wouldn't likē to bet on which connection is bad, but it would probably be worth checking all of your earth connections, starting with the battery/engine/chassis one. Might be worth checking the battery voltage at cold start too. If none of this throws any clues up, then bad connectionß on th live side my be to blame, possibly in the fusebox area. Does everything else work as it should and no suspiciously dim dashboard lights etc?

The battery is new and has been checked and all is fine. I admit I haven’t personally checked the earths.

everything else electrical works exactly as it should instantaneously. Dash lights etc are all as they should be.
I did wonder if it may be an alternator issue.....

[Doctordiesel77]

Sounds as though the alternator is working, if it is voltage related, then the voltage must be increasing after start up. First thing to check is the switch, as Jeff says they have been known to be naughty and it is fairly easy to test.I thought it seemed odd that it is alway ok when engine is warm, but I hadn't thought of vibration affecting it. One of my switches failed because a wire broke, it worked sometimes as the wire was sizzling itself back into the solder! If everything else is 100% ok, then the earths sound less likely.