Hello...For the most part, I rely on Chevrolet to maintain and work on my '03 C5. Today, I stopped in to see if they'd install LED headlight bulbs (FAHREN 9006/9005). Yes they will, but my service "adviser" told me he wouldn't do it because it may lead to electrical issues.
I'd appreciate any comments or feedback in order to make an informed decision. Thank you.

 

You'll have to either turn off your lights with the car running or put them on high beam if not running to lower them. Other than that they are blowing smoke.

 

 

No problems whatsoever for me, no issues opening or closing lights regardless if engine running or not.
I would've asked that adviser to spell out what issues he thinks can happen.
I would just change them yourself, it's a simple job.

 

BEWARE...I took it to a Chevrolet dealership to install the LED headlights. Reason is...This dealership has a mechanic, with 25+ years of Corvette expertise and it shows. He's sharp and very thorough. He got 3 of the bulbs in. The 4th one caused all of them not to work properly!. Prior to starting, he told me not all corvette can handle them. He sees more and more Vettes come in with "electrical problems" related to LED headlights.

 

He probably means people have issues with LED bulbs in general not just headlights. Either he sucks at giving details or you're not relaying the info.
What happened exactly when he put in your bulbs? What does "not work properly" mean?

 

Not sure im curious about this same issue. I've seen them with and without the boxes. I have led taillights and front market lights which does cause the hyperflash and does sometimes throw the rear and front codes for the ride control or whichever i read the brake lights run into the same wiring which causes those codes. It doesn't cause any drivability problems just the car throws the codes sometimes not so much after a few key cycles.

 

sometimes without load resistors, the LEDs don't draw enough power to trigger the motors to recognize when the low beams are on or off. that also depends on the manufacturer of the diodes.

another consideration is the physical design of the replacement lamp. some are physically too big (heat sinks or fans) to fit in the space behind the lens without hitting the brackets or raising/lowering brackets.

 

I think they determine that a bulb is out which usually cause the blinkers to blink fast as the LED dont draw enough power as regular bulbs.

 

I've gone pretty much as far as one could go with LEDs on my 02 Z06....LED headlight bulbs, LED taillights, LED interior bulbs, LED under-hood bulbs, etc. etc. No issues whatsoever except hyperflash which is normal and easily solved with a hyperflash harness.

And I've been on this forum for years and I haven't heard of other C5 owners having unusual electric gremlins caused by LEDs.

 

For my first post I found an issue I am having. Just bought an 04 vette with led headlights installed by the previous owner. either you shut them off when running, or turn the brights on when not running to get the lights to retract. Very high annoyance factor, but seems to function fine. Has anyone found out if there is a resistor or capacitor or adapter out there you could plug or splice in somewhere to fix this? Any known fix? Is this a low amp draw issue or something else?

 

I have 4 codes for DRL relay circuit im guessing because i have rear led tail lights and front side marker lights. Will the hyperflash module get rid of these codes? I also have a bad 4157 LED side marker light that when blinking for 15 seconds stop blinking and start blinking again. I replaced it with a new LED 4157 and had no blinker problems since. Hope this helps.

 

I have not had any codes for the other lights but Ill double check when I have a minute to plug in the code reader. Thanks.

 

It shouldnt cause any other issues other then hyperflash as led take less voltage and sense a dead stock bulb causing the hyperflash. I have these for for DRL relay circuit. B0502 B0503 B0507 B0508 all 4 for DRL relay circuit. All my lights function but do hyperflash blinkers. Does anyone know if the hyperflash harness will get rid of these 4 codes? I like the idea of the blinkers hyperflashing looks to be emergency but i like less codes on the DIC sensing trouble.

 

This is a very well known occurrence and once you are on the forum for a while you will see it.

Read post 3 here (igore the last part about the flasher button - that was for something different).

You DO NOT have to install load resistors - they defeat the purpose of installing LEDs in the first place.

https://www.corvetteforum.com/forums...-blinkers.html

 

Dash continuity? Never thought of that. Is there a diagram/instructions you could send me or pm me for the relay fix? I'm unclear what actuates the relay itself, so I am sure I don't fully understand your solution. (I do have a ton of stuff to learn about this car) Many thanks.

 

All you need to do is connect pins 85 and 86 or a relay to the - and -+wires for the low beam on the driver side. You could even install a mini bulb (tiny). All the module needs to see is the continuity through a filament or the tiny resistor in a relay (NOT A BIG POWER RESISTOR THAT EVERYONE INSTALLS). The lights will then close properly.
When showing this to Sharplight innovations I sent George video of mine opening and closing with no lights installed. The relay needs to use an internal resistor (not a diode) with pins 85 and 86 then connection will not be polarity sensitive. The pic shows it reversed because it was a quick napkin drawing. If you don't know what this means, just be sure to connect pin 85 to the - wire. Attached are two pictures I sent George at Sharplight and the one that shows what to build he has actually been using to fix complaints of headlights that would not retract with his kits. The reason he was having issues is that he wires directly to the OE connectors instead of using OE connectors to power relays to activate lighting.
I also gave this solution to people on the C5 Modified page on facebook and they have been very happy.




Here is a post of what one guy did after I explained it to him - he built the connector above rather than simply splice into the two wires.
"Change headlamps to LED’s. Problem was headlamps would not go down since LED’s don’t have any resistance like a bulb does. Here is the fix so car works like factory. I purchase 9006 extensions and 30 amp weather proof relay and harness. You only use pin 85 which connects to low beam power wire. Pin 86 to negative low beam wire. You don’t use any other pins from relay. Relay has resistance built into it, so car thinks the bulb is lite. You only have to do this on passenger or drivers low beam not both. Advantage is relay has no heat like resistor. Extension I liked cause we didn’t cut into factory harness and car can go back to factory if you ever wanted.
Hope this helps others and thanks Ed"

 

Now I see..... What a simple, elegant fix. Many thanks and I'll see how this works for me.

Bill

 

Glad to help. It kills me seeing people install big power resistors that get hot and just draw current. One of the benefits of LED is less electrical draw and then they install huge heat sinks.

 

Just what I needed, thanks