Demister + Hazard Light

[89CAL]

Hi

I was pretty sure there was a post on here somewhere about doing this, but I cant seem to find it

Basically Ive already got the blue dash and air con lights, my hazard switch light has never worked, so thought I would try and fix that and while im at it make everything blue

Ive bought 2 x 3mm Blue LED's which had a max volatage of 4v from what I can see. But I thought stuff it there only 50c each I'll give it a go and hopefully it will only draw a few volts. But its blown the light by the looks of it as soon as I've tried it lol.

Basically just wanted to see if anyone else has done this? I'm guessing unless I can find a 3mm 12V Blue LED im going to have to get a resistor and put it in the wiring before the switch as its the only real place where there is room for it.

The only reason I'm posting this here is because I'm sure I've seen it in a thread somewhere where someone had done this with a 12v 3mm bulb, but it could have just been a normal globe not an LED

any help would be appreciated

Thanks

Callan

[R33shaun]

For any LED youll need a resistor in series to limit the current, go to jaycar or somewhere similar and buy a 220 Ohm resistor that'll give you around 55mA across the LED and itll be all good cost the whole of 20c. Then soldier the resistor to one of the LED legs and wire in normally (make sure you put the LED in the right way as there polarity sensitive)

[89CAL]

yeah figured as much. I guess the wedge type ones have a resistor built into the base.

Ill have to wire the resistor into the wire before it plugs into the switch because there is no room inside the switch where the light sits to put a resistor, the legs come straight out of the LED and go basically 180 degrees then straight then 180degrees again, over a very small space

Thats fine but, 220ohm resitor will do the job you say? I could work it out, but if your sure thats what it is, it saves me some maths

Thanks

[R33shaun]

220 Ohms will give you 55mA which should be fine but itd pay to check the current rating of the LED and you can put it anywhere in the wiring as long as its in series.

[89CAL]

peak forward current = Maximum 160mA

forward current = Maximum 20mA

Cant work out if that means I should put max of 20mA or 160mA....

its only a little baby LED. 20mA is probably plenty

[R33shaun]

peak forward current is the max it can take b4 it blows and it wont take that much for long.

for 20mA use a 600 Ohm resistor (or anything close to that it doesnt have to be exact)

[89CAL]

yeah just worked out 600ohm, sweet. Will give that a go, might post up some photos when I'm done if I remember

Thanks mate

[PLYNX]

I did mine a while ago and changed the dimister to the a green/blue colour to match the aircon controler readout and the hazzard in red. It was a bit of a fiddly job to get them in the original rubber slieve bulb holders but it looks great now. I also did the AUTO switch on the drivers side power window switch

[89CAL]

Alright I sorted it

Got a high intensity blue LED and put it in the holder for the light in both the switches. Then wired a 620ohm resistor into the light illumination wire.

Ill see if I can do a rough drawing

Hazard

Demister

- - - -

- - -

+ - - -

+ - -

Thats looking at the plugs coming from the car side. The + symbols are the wires in question. I think the demister may be the other way around (Bottom right wire not bottom left) but cant remember and my dash is back together

anyway, it should be the blue with red striped wire. Theres one in each of the plugs, thats the wire for the illumination

Hopefully that helps someone

BTW: sorry about the formatting of the 'drawing', cant remember how to get it to space normally lol

Edited November 29, 2010 by 89CAL