LED Instrument Bulbs

[ptjs1]

Apols for posting in multiple sections of the BB. I'm just trying to find a member who may understand LED electrics!

After 12 years of frustration at the appalling design of instrument warning lights on a facelift XJS convertible (ie invisible!), I've finally decided to do a fairly cheap upgrade by putting LED coloured bulbs in place of the standard B8.5D bulbs.

I thought it was going to be fairly simple but have discovered that there is a potential issue with 3 of the bulbs. These are the Sport Mode illumination bulb, 1st gear lockout illumination bulb and the Check Engine Light circuits. For some reason they are linked into circuitry which seems to give the bulbs a constant current draw of .01v (as measured on my voltmeter) when not in use. This doesn't cause a problem normally as it doesn't seem to cause any illumination of the standard bulbs. But those who have changed to LEDS report that the bulbs then become faintly illuminated all the time. And apparently if you then leave a standard bulb in the Sport Mode slot, then the 1st gear lockout LED won't work (presumably because the circuits are deemed to be mutually exclusive).

Now I'm guessing that this is because an LED chipset can operate at much lower volts and therefore the LEDS glow with even .01v applied. My question is would an LED bulb with 2 LED units be less likely to illuminate with .01v applied than one with one LED unit? My naive logic says that it would still glow dimly with 2 units, but maybe there's something in LED current draw which would mean that the more LED units are in the chipset then the less likely it is to glow with a tiny voltage of .01v applied? Does that make sense? If so, I'll fit the more expensive 2 unit bulbs to the problem circuits.

I'd appreciate any thoughts on the above.

Tks

Paul