Another CHMSL LED Conversion

[Paul Workman]

Originally Posted by Jagdpanzer

Tail lights are already converted to LED. Conversion kit came with load resistors so I used them. They only come into play when the turn signals are used so additional energy use is insignificant.


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We're on the same page, Phil.

But, for those unfamiliar and want to better understand the LED conversion(s), it may help to know that the actual solid state (NP junction) "chip" itself has a very low (threshold) resistance; which would actually act like a short were it not for the high value resistor incorporated (in series) into the (automotive) LED conversion "kit".

This high value resistance poses no problems in some circuits and actually results in a significant reduction in the load associated with the stock light bulbs. However, certain relays and blinker switches (in particular) actually depend on the higher current load of stock bulbs to operate. So, when an LED (kit) is installed, the current drops to nill and then those relays and blinker switches fail to operate.

So, what a "LOAD RESISTOR" does is emulate the (lower) resistance of the stock light bulb path to ground. Thus those devices that rely on the higher (stock) current draw (due to light bulbs comparably low resistance) will operate as before the introduction of the LED kit.

To avoid having to use LOAD RESISTORS, some new circuits are designed which operate independent of whatever the load is. Such are the case of the "LED" blinkers. By installing these special upgraded blinker switches much or most of the need for LOAD RESISTORS is eliminated in many (or MOST) cases.

LEDs require very low POWER (voltage X current) to produce light compared to incandescent bulb (filaments). And, LEDs emit light without having to be heated first; responding practically instantaneously when voltage/current is applied. And, they stop emitting light the instant power is removed: there is no lag time to come on or turn off like incandescent lights do.

So - for anyone that was wondering what and why "LOAD RESISTORS" were needed in some LED conversion and not others, I hope this helped!