CHMSL LED mod

[GOLDCYLON]

Originally Posted by spork2367

Have you done the calculations for any of this? Lets say every auxiliary light on the car (minus headlights and fog lights) draws 200 watts (my ballpark for our cars with brakes being applied probably accurate +/- 20 watts). That's about 17 amps. If you replaced them all with LED's, you could expect to cut that down to 6-10%, so you'd have 1.7 amps. So for approximation sake, best case, you save 15 amps. The 16 inch spal fans are 26 amps. I can't believe the alternator is so undersized that it can't accommodate the fan as is, but if that is the case, saving 15 amps isn't exactly a huge safety margin as you're still asking 8-10% more of the alternators max output.

If you're just talking about the CHMSL, it uses four #891 bulbs at 8 watts a piece for total of 2.6 amps.

If you swapped every exterior light on the car to an LED (including fog lights and headlights), you still wouldn't save the 26 amps a 16" spal uses. Total exterior light usage is 27 amps. Keep in mind, the power supplies used for LED fog lights and head lights are not as efficient as those used in small bulbs and they require significantly more power. So while a tail light LED may use 6-10% of the power of a standard incandescent, an LED headlight will be closer to 30-50%. Especially considering the original headlights were low wattage even by todays standards.

Other solution is...not using your brakes will save you 11 amps!...

Just some food for thought.

Lol that’s a lot of food there... and Math arrrrgggghhh. I have the interior kit, the headlights, the tail lights, side markers, backup lights, reverse lights, license plates lights and the spare tire light. All LEDs. I did not do the math (thank god for ken in Apollo 13 who just kept working the LEM startup sequence while the engineer ran the ammeter and the coffee pot) and I am running dual Dewitt spal fans with a standard alt with zero issues. Pretty much everything with the exception of the headlights and tail lights was bought online at super bright LEDs.

[GOLDCYLON]

Originally Posted by secondchance

Which LED do you recommend for tail/brake lights and side markers?

Speak to -=JEFF=-

[GOLDCYLON]

Originally Posted by secondchance

Which LED do you recommend for tail/brake lights and side markers?

For the tail lights I went with the multiple LED model and did not just replace the bulb. The model I went with replaced the entire rear lens. Been running that on my white car 13 years and it’s also on my 90 and my sons 96 GS.



I did this for safety really. One time in a 14 month period my GMC Jimmy was rear ended 3 times in 15 months. The Vette is so low and I am always waiting on the Azz hat to jump into my lane daily at least I have done everything possible for them to see me including running DRLs on ALL my cars. My forum bud Dom hates this model because it makes a little cross for a light and honestly I get that but I agree it would have looked a little better if they had added one more LED to the top second and second from the bottom row which would have rounded it a little more. The brightness even in full AZ sun is outstanding! GC

[spork2367]

Originally Posted by GOLDCYLON

Lol that’s a lot of food there... and Math arrrrgggghhh. I have the interior kit, the headlights, the tail lights, side markers, backup lights, reverse lights, license plates lights and the spare tire light. All LEDs. I did not do the math (thank god for ken in Apollo 13 who just kept working the LEM startup sequence while the engineer ran the ammeter and the coffee pot) and I am running dual Dewitt spal fans with a standard alt with zero issues. Pretty much everything with the exception of the headlights and tail lights was bought online.

So based on rough math, during nightime driving conditions (when interior lights aren't on) you're consuming about 5 amps more than the car did stock.

One thing this doesn't take into account is the operating time of the spal fans vs stock fans. The fact is, once you consider the stock fan amperage the difference is probably miniscule.

[GOLDCYLON]

Originally Posted by spork2367

So based on rough math, during nightime driving conditions (when interior lights aren't on) you're consuming about 5 amps more than the car did stock.

Which is my guess is why the stock alt can handle the draw It’s just 5 amps.... right? Also don’t forget the SPALs do not always run.

[GOLDCYLON]

Originally Posted by spork2367

So based on rough math, during nightime driving conditions (when interior lights aren't on) you're consuming about 5 amps more than the car did stock.

One thing this doesn't take into account is the operating time of the spal fans vs stock fans. The fact is, once you consider the stock fan amperage the difference is probably miniscule.

My thoughts as well and concur.

[secondchance]

Worst case scenario for Spal fan would hot summer day, AC on full blast in stop and go traffic. Not gonna do math though...

[GOLDCYLON]

Originally Posted by secondchance

Worst case scenario for Spal fan would hot summer day, AC on full blast in stop and go traffic. Not gonna do math though...

Me neither. But it is interesting to know what the numbers are so you DONT overload or the alt with mods. If you continue lmk. I have been there done that lol

[secondchance]

I have converted to LED headlights, HID driving (fog) lights and of course LED CHMSL and LEDs for all interior lights. Now, looking into LED tail lights.

Obvious benefit for these conversions are extra illumination (especially head lights), reduced electrical load and longevity of bulbs. My understanding is (and I may be wrong) that, even if functional and not so apparent, excessive electrical load can result in short service life for alternator.

[GOLDCYLON]

Originally Posted by secondchance

I have converted to LED headlights, HID driving (fog) lights and of course LED CHMSL and LEDs for all interior lights. Now, looking into LED tail lights.

Obvious benefit for these conversions are extra illumination (especially head lights), reduced electrical load and longevity of bulbs. My understanding is (and I may be wrong) that, even if functional and not so apparent, excessive electrical load can result in short service life for alternator.

I agree but even if the math is right 5 amps isn’t going to do it. Without doing the math I’m fine otherwise the amp meter in the car and the car would have something to say about being under volted. GC