Another CHMSL LED Conversion

[Jagdpanzer]

Got called out by another WAZOO brother that one of my CHMSL lights bulbs was out. Decided to convert to LED. Did some poking around on Amazon and came across this slim 12" LED light bar that look promising.
16312
Trimmed the mounting ears off and it fit nicely into the CHMSL housing.
16313
The existing light bulb holder serves as a retainer. Required some minor trimming to get everything to fit snugly in the light housing.
16314
16315

Final results
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[Jagdpanzer]

LED bar part number: ‎GTCV-0475639081


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[RICKYRJ1]

very nice, well done :thumbsup:

[HAWAIIZR-1]

Another mod done to perfection Phil! Thanks for sharing.


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[We Gone]

Nice a new winter project

[dredgeguy]

Looks great Phil!

[Great White]

LED CHMSL was the first modification I did on my Z. I don't even think I had licensed the car yet!

I just used the "ultra bright" Red LED adhesive backed strips from Advance Auto Parts and soldered the wires. They've worked great for the past 4 years.

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[Paul Workman]

:thumbsup::thumbsup::thumbsup:

Great post. Thanks! Have U converted your tail lights yet? if you do, you'll want to install an LED "blinker" switch in place of the stock blinker. That will eliminate the need for any LOAD RESISTOR considerations.

[secondchance]

:thumbsup::thumbsup::thumbsup:

Great post. Thanks! Have U converted your tail lights yet? if you do, you'll want to install an LED "blinker" switch in place of the stock blinker. That will eliminate the need for any LOAD RESISTOR considerations.

Spoiler - he has converted and it was blinking fine. I followed him to a local car show.

[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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[Paul Workman]

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.:thumbsup:

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-0475639081&crid=T830B1FTP4KD&sprefix=gtcv-0475639081%2Caps%2C65&ref=nb_sb_noss

[1991 Corvette ZR-1]

Amazon still has them.

2 per package, $16.31

https://www.amazon.com/s?k=gtcv-0475639081&crid=T830B1FTP4KD&sprefix=gtcv-0475639081%2Caps%2C65&ref=nb_sb_noss

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

[1991 Corvette ZR-1]

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]

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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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.

[Subfixer]

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.

I know what you mean.
I was a C2 guy for 17 years prior to my ZR-1 purchase, although definitely NOT numbers matching.

[Prez1967]

very tempting as its a very inexpensive part but i've told myself that I will not convert to LED.... I do have a bulb out up there

[1991 Corvette ZR-1]

very tempting as its a very inexpensive part but i've told myself that I will not convert to LED.... I do have a bulb out up there

It was not too bad. The worst part was the careful removal of the large grommet around the wires going into the halo. Some WD40 and gently squeezing and working it out with needle nose pliers worked eventually. Just take your time. I used automatic wire strippers to grab the two wires going to the circuit board inside the factory light and was able to pull the coating back enough on each. Then I used a pick to gently make a hole in the bare stranded wiring so the stripped wire from the LED could tie into them.

I had the LED ready for install in about 30 minutes after sawing off the mounting tabs and clearancing the back of the LED plastic so it could seat in between the light shells and lense. Jagdpanzer?s looks brighter than mine but mine ended up looking just like the factory lights. The big benefit of less amp draw was worth the time to fit it.

Edit: As I sit here after this initial post it hit me. Maybe Jag?s looks as bright as it does because he tied both power wires into the factory power feed side. I have Zevo red LED bulbs showing up this week for the four bumper lights. If they end up brighter than the CHMSL I may go back in there And try tying both wires into the power side as my OCD would bug me if the brightness is not similar across all brake lights.

[Subfixer]

I don't think mine ended up any brighter that the original, but there's a more complete look to it vs 4 bulbs.
My tail lights are LED also.

[1991 Corvette ZR-1]

I don't think mine ended up any brighter that the original, but there's a more complete look to it vs 4 bulbs.
My tail lights are LED also.

Did your lenses come out easy? Mine are ON there. Removed the screws and it is like they are still in. Sadly, I think this weekend I will be doing the old 84 to 90 bulb change method to remove the whole housings. I can?t believe how stuck on there the lenses are.

[Subfixer]

Those lens gaskets can really get stuck. I just took my time with plastic tools to get mine off.

[Mikey]

Why not just install 891 / G4 LED bulbs replacements in the original sockets?

[Jagdpanzer]

For some of us that would be to easy.


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[1991 Corvette ZR-1]

Why not just install 891 / G4 LED bulbs replacements in the original sockets?

Honestly, it never crossed my mind. I figured the style of bulb for these old cars was a non starter for the modern LED bulbs available. Do they make these in red tint?

[Mikey]

There are a couple sources for red LED 891/G4 bulbs. But you can also use white LED. Someone would have to try a few out to determine best choice. They're not all the same size even though it's a standard 2-pin base.

[1991 Corvette ZR-1]

Since this is LED related discussion, I have encountered a hiccup in my install of the rear four tail lamps. I used Zevo 1157R and they light up great. Problem is they will not indicate a turn signal. It is just a solid state of being on for whatever side is being used to signal. Swapped in old bulbs to make sure it was not the switch that had coincidentally gone south and sure enough they blink.

Hazard flashers on and the LED tail lamps do flash. So is this the case of a required relay to make them play nice when using the turn signal switch? Both hazards and turn signals use a flasher buried in the dash but find it weird the signal flasher is not cooperating like the hazard flasher does.

[Subfixer]

You need a solid state flasher. You can get it at any parts store. Hard part is replacing it under the dash.....
Standard Flashers work on current to heat up a bimetal strip which causes the flashing. As the strip heats and cools, it makes the lights flash. LEDs do not draw much current, so the signal lights won't flash. The hazard lights flasher is working because all 4 tails and both front provide enough current for it to work.

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[secondchance]

Since this is LED related discussion, I have encountered a hiccup in my install of the rear four tail lamps. I used Zevo 1157R and they light up great. Problem is they will not indicate a turn signal. It is just a solid state of being on for whatever side is being used to signal. Swapped in old bulbs to make sure it was not the switch that had coincidentally gone south and sure enough they blink.

Hazard flashers on and the LED tail lamps do flash. So is this the case of a required relay to make them play nice when using the turn signal switch? Both hazards and turn signals use a flasher buried in the dash but find it weird the signal flasher is not cooperating like the hazard flasher does.

I am using Zevo 1157R also. Replace flasher with LED type and blinker will work.

[tf95ZR1]

About electronic flasher:
https://www.corvetteforum.com/forums/c4-tech-performance/3524632-electronic-flasher-needed.html

Install:
http://www.zr1.net/forum/showthread.php?t=23326&highlight=flasher

[-=Jeff=-]

Since this is LED related discussion, I have encountered a hiccup in my install of the rear four tail lamps. I used Zevo 1157R and they light up great. Problem is they will not indicate a turn signal. It is just a solid state of being on for whatever side is being used to signal. Swapped in old bulbs to make sure it was not the switch that had coincidentally gone south and sure enough they blink.

Hazard flashers on and the LED tail lamps do flash. So is this the case of a required relay to make them play nice when using the turn signal switch? Both hazards and turn signals use a flasher buried in the dash but find it weird the signal flasher is not cooperating like the hazard flasher does.

Turn signal Flasher is separate form Hazard, like it was stated an electronic flasher for the turn signals will work, I swap both flashers in my car for electronic

Hazard flaster is on the passenger side of the car under the dash

[1991 Corvette ZR-1]

Thanks, all. I got my new LED flasher and installed it and the rear lamps signal properly. Loving the reduction in amps pulled. Wondering if I should just go full LED up front as well to match the CHMSL and the four brake lights. Any recommendations for brands to use for side markers and fronts? Looks like I will need a new hazard flasher if the fronts are replaced.

[-=Jeff=-]

Thanks, all. I got my new LED flasher and installed it and the rear lamps signal properly. Loving the reduction in amps pulled. Wondering if I should just go full LED up front as well to match the CHMSL and the four brake lights. Any recommendations for brands to use for side markers and fronts? Looks like I will need a new hazard flasher if the fronts are replaced.

I believe the 91 is the same as the 1990.. you may run into issues doing that due to voltage direction on the side bulbs along with grounding

[Andy]

Paul Workman wrote a multi part how-to for the HoTB. Issue 51, or there abouts. They cover most of your questions.

[aafc]

I was looking at my runs on you tube at Orlando Speed World Jan. 9 ,2022.
that is when i noticed that my CHMSL had a light burned out. Ordered the
light bar (2) to a package, installation was time consuming because of the
roll bar in the car and I don't bend as easy as I use to do. But I got it
installed without too much trouble. (hint if you can't bend get someone who
is more agile to help you).My wife saw the new light and said that it looks a
lot better.
John
1990 black/white # 2546
one of a few 4l8OE EQ ZR-1's

[1991 Corvette ZR-1]

I have officially gone off the LED deep end. Decided to try under hood LED lights to replace the factory bulbs. I found some that are 640 lumens each and boy is it a world of lighting difference. Now I know these are nothing new but I am guilty of loving ZR-1s a little too much. I like to keep my hood open and look at the LT5 more than I care to say but lets just say I would have a dead battery many times over if I kept everything factory.

So I wired in a switch off the orange wire going to the under hood fuse. I tucked it inside the front crash impact pad so it is safe from water during rain or car washing days. Came out pretty well for a clean install I think. Here is the link if anyone wants to give them a try. Not bad for $11 or so.

On the pics and I am sorry they are lopsided, the forum for whatever reason rotates them when uploading. One of the pictures I covered the LED with my hand to show the stock bulb brightness. The other pictures with both LEDs in, the lights in the garage are off. That is all LED light in the pictures.

https://www.amazon.com/gp/aw/d/B07JQDJC1F?ref=ppx_pt2_mob_b_prod_image