Hi, only some of the LED's need soldering the ones in the A/C do not, they need unwinding drilling out and re winding with the new leds.......all the info is in the thread i posted its a bit all over the place but it is all there.
Blue or red come out best Green makes the Gauge needles very hard to see at night.
Blue looks very good....thats why most of the UK skylines have this mod.
And remember the LEDS only work one way round so if it does nt work turn it round...easy in the gauge cluster not so easy when you ve just soldered them in and both are wrong, AARRGGGHHH