Drive lights - delay to dip

That is a very big relay put a diode on the switching wire to stop back EMF.
Thanks Graham

G'day Allan,

I had a sticky relay on my driving lights some years ago. Played up for a while & then while driving back to Melbourne on the Princes hwy went to dip the lights & the driving lights just stayed on!
I was real popular with the oncoming traffic trying to pull over as fast as I could without blinding everyone. I did not have a separate switch to disable them so
disconnected them for the trip home then changed the relay & never had another problem with them till I sold the car.

For interest sake I pulled apart the failed relay & the contacts had fused together.

Hope this helps

Cheers
Stu

Gooday Allan :The other Allan might have more of a clew But I would change the relay , I had a similar problem were the spots wondnt turn off changed relay sow far ok .
cheers nick

Thanks for the advise everyone. I'll try a diode first as the relay was a bit expensive. I used the 100A relay as I was having trouble getting two spot looms and relays to play nicely together through one cabin switch, ( I have two sets of drive lights ) so I just ran all the lights through the one relay. Has worked great for a couple of weeks. I guess there is not a lot else in the circuit other than the relay or a connection to go wrong.

Hi Allan, Allan here.

There are a number of possibilities but without knowing your exact wiring arrangement I can only suggest some possibilities.

The fact that the relay drops-out as soon as you operate the cabin switch suggests that it is not a sticky relay. The fact that the system worked OK following installation suggests that the circuit is correctly arranged.

What comes to mind is that the voltage applied to the relay is not falling to zero when the high-beam goes 'off'. In other words, enough voltage to hold the relay energised is still present when switching to low-beam. Some 12v relays only need several volts to 'hold-in'. This voltage could come via the high-beam filaments or the drive light filaments if their earth connection was not 100%. If you have a voltmeter apply it to the coil connections of the relay whilst it is in the faulty state and if it reads even just several volts, then it indicates that problem. If so, check the quality of any earth points of your headlights and driving lights.

A diode across the relay will not cure your problem, but it is a good thing to have anyway. Connect the diode directly across the relay coil with the "banded" end of the diode on the positive side of the coil. Get it the wrong way round and you create a short-circuit!

I have that exact issue now, first thing I will do is change the relay

mine actually stay on though and i need to quickly turn the headlights onm and off to extinqish them

let me know how you go im going back to work and will address it on my return