hazard bulb

[ferny]

The Mazda has a constant 12v feed off its relay which you earth to make the hazard circuit. I've bought an illuminated switch for it but the bulb doesn't illuminate when the hazards operate which I assume is down to its element not getting hot enough during the time it has current running through it. I've tried one of my green LED bulbs with a 500 Ohm resistor which makes the LED come on, but the hazards aren't working. Without a resistor the hazards work but the LED stays on constant.

With a bit of digging I've found out the Mazda uses a 65mA bulb in its switch (link below). Now, I threw out the switch long before I decided to use the Mazada flasher relay... Can anyone see why swapping the bulb for the correct one from Maplin wouldn't work? Just thought I'd check before nipping out to buy it.

http://www.maplin.co.uk/p/coloured-subminiature-bulbs-red-pg78k

[DougBGT6]

I assume is down to its element not getting hot enough during the time it has current running through it.

If it was an electric fire element, yes, but an indicator bulb? No. Haven't you got another one you can try, out something else?

[ferny]

Tried 1.4w, 2w, 5w, etc. Only the LED illuminates yet all the others complete the circuit without glowing.

[DougBGT6]

Sounds like time for the trusty voltmeter. See what happens to the voltage across the bulb with the flashers on. Should give you a clue. I might put an old rheostat in line with the LED and turn it down till it all works, or not!  :-/ Then you'll know what resistance you'll need.

Or, just found this:

http://led.linear1.org/1led.wiz