Engine warning light from 94 GM 3.4 PCM

[limey222]

A very simple question, can anyone see a reason why I can't use a small 12v red led pilot light to signal a fault condition?  I am concerned about it having too low a resistance to ground unlike a conventional bulb.

See: http://www.ebay.com/itm/321705079086?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[limey222]

 -- moved topic --

[kstevusa]

Should be OK, I used a orange LED for C E L.

[MGBV8]

Generally, you use a resistor with a LED.

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

[kstevusa]

I just ordered an Orange 12V. led from Speedway motors assortment and connected directly to the feed from my ECM.  Nary a problem, it has illuminated; so it works.  No parallel series so is resistor needed?

[danmas]

Generally, you use a resistor with a LED.

When you buy an LED labeled for 12 volts, such as these, it will have a resistor built in.

[MGBV8]

Right, Dan. I was thinking of a bare bones LED.  



Kelly, in series in a basic LED application to limit the current (& adjust the brightness).

[danmas]

... in series in a basic LED application to limit the current (& adjust the brightness)

Carl,

I used the LEDs shown in the top pic in my MG. The blue LED high beam indicator was blindingly bright compared to the others, so I had to add a resistor in series to tone it down a bit.

[kstevusa]

OR, just purchase from Speedway, solder and shrink wrap & mount.  No reason to complicate things  :-)