The previous owner of my 110 Defender fitted a front bumper with rectangular led daylight running lights. Shortly after I bought it last August the RHS DRL failed. I eventually replaced it in December and it also failed within a few months. I replaced it and it has now also failed.

Each time some of the leds begin to flicker and eventually they die completely.

I read somewhere that it might be due to voltage spikes but I can no longer find the info on the web.

Anyone got any wisdom (aside from ditching the DRLs)?

Check the voltage across the battery while the engine is running above tickover, that is when the system is charging. If the voltage is above about 14.5 volts then you might have a problem with either the alternator or the battery (or both). You should also check carefully the circuit which decides when the lights are active.
Looking for and measuring spikes on a DC supply is going to require the use of an oscilloscope and as such is usually beyond the availability and ability of the ordinary motorist. Measuring residual AC on a DC supply can be done with a multimeter, but it does require a certain level of electrical knowledge to interpret the results.
An auto-electrician should be able to conduct the various tests on the vehicle system to rule out any faults.
Other than that, I like your own suggestion; they aren't needed, they aren't legally necessary and the things are the work of the devil .... get rid!

Much appreciated. It's very odd because only the RHS ever fails.

I'd disable both, hatefull things.

Dazzle, hide indicators, need banning unless simialr to the old Volvo ones