Oil and Volt Guage Led wont stay on!

[wardyworld]

Hi all,

Just put some leds in my oil and volt guages - decent ones in OE holder.

The volt led keeps going on and off! Its driving me nuts!!!!! To try and cure I have:
swapped the leds (i have 4)
put the volt led in the oil led which is then fine (so i dont think its the leds)
Moved the led about in the holder - if I wiggle it to the right point it will stay on as soon as i try and put the holder back in - it goes off
I've taken the assembly apart - cleaned it all - still it does it.

Annoying when it flickers as your driving at night!!

Any ideas whats causing it guys?

Cheers for the help,

wardyworld.