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!

[Subfixer]

Just picked up the same light bar as Phil's from Amazon (thanks for the link). Only $17 and change for a pair. So I have a spare. My weekend project.

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[Subfixer]

Following Phil's instructional post, I got mine done today.

[1991 Corvette ZR-1]

Is there another place that might sell these? I plugged in the part number in Google but it much luck.

[Subfixer]

Amazon still has them.
Partsam 2Pcs 12" 15 LED Red Led Trailer Truck Identification Light Bar Waterproof Sealed Thin Stop/Turn/Tail ID Marker
2 per package, $16.31

https://www.amazon.com/s?k=gtcv-0475...ref=nb_sb_noss

[1991 Corvette ZR-1]

Originally Posted by Subfixer

Amazon still has them.

2 per package, $16.31

https://www.amazon.com/s?k=gtcv-0475...ref=nb_sb_noss

If it had been a snake it would have bit me huh? Good looking out!

[1991 Corvette ZR-1]

Originally Posted by Subfixer

Following Phil's instructional post, I got mine done today.

Did your LED have three wires? I see the wires coming off the CHMSL is only two. How did this wire up? The LED has white, red and brown wire.

[Subfixer]

If I remember correctly, I used the red and white wires. You can test this by hooking up the wires to a battery. Red positive, White negative.
Since these are for a trailer, both dim (running lights) and bright (brake/signal) options are in the Led strip. The brown wire is the less bright of the two. I just cut it short and sealed it so it wouldn't short against anything.
When you hook it up to the existing connector, ensure you have the polarity correct. LEDs only work in one polarity. Test it before final installation.

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[1991 Corvette ZR-1]

Originally Posted by Subfixer

If I remember correctly, I used the red and white wires. You can test this by hooking up the wires to a battery. Red positive, White negative.
Since these are for a trailer, both dim (running lights) and bright (brake/signal) options are in the Led strip. The brown wire is the less bright of the two. I just cut it short and sealed it so it wouldn't short against anything.
When you hook it up to the existing connector, ensure you have the polarity correct. LEDs only work in one polarity. Test it before final installation.

Sent from my Pixel 4a (5G) using ZR-1 Net Registry mobile app

Thank you for the info, sir! Add another owner to the LED CHMSL club. However it is not as bright as Jag?s appears to be. It actually looks to be same brightness as the factory bulbs I removed. Although to be fair, I hooked up two 9 volt batteries to test the brightness off the red wire and it was super bright. Most likely because it was running 18 volts instead of the vehicles 12 volts. Not sure if it gets brighter with the car running but nice to know that?s about 2 amps less being pulled for brake lights. Zero red LED lights showing up soon for the four tail lights.

[1991 Corvette ZR-1]

Oh and some most likely pointless pictures outside of someone wanting to document numbers on everything. The ZR-1 group is the most fanatical besides the C2 guys so you never know. Both sides of the rubber gasket under the housing. Vintage 1991 documentation. Amazing this thing has been in place for 31 years.