quote Originally posted by thesameguy: How can amber vs. red be illegal? Mountains of cars have no amber lights whatsoever, and sometimes manufacturers switch within a single model in a single year based on trim. I think an example is the Focus SVT - regular Focus has a red turn signal, SVT has an amber. I think Honda did the same thing with the Civic Si vs. all the other Civics. Pretty sure the color is not the issue - red or amber are both acceptable in the US. The issue is that all lighting has to be DOT approved, and if it's not it's illegal. Given how many people ran around with knock-off "Altezza-style" lights back in the Fast & Furious age, I think it's far to say nobody really cares.

Both colors are legal and wiring is different to make them work. Even on cars w/ close to same trim.

Amber Turn CAN work at the same when Red Brake is on because other drivers can see the different colors. Amber is turn signal regardless Red brake is on/off or whatever. Even tho a light meter shows same output, Amber is brighter then Red to most people so very hard to confuse the two.

Almost all cars and trucks sold in the U.S... (Might be a few exception but I've never seen one.) On the side w/ active turn signal, Red Turn will Cancel Red Brake to prevent confusing other drivers.
Because Many times the brake light blink too when people slow down or stopping because people don't push the pedal constantly. When that happens, w/o canceling the Red brake, hitting turn signal to change lanes etc often can not be seen by or confusing to other drivers.

That's what the problem is here...
GT wiring was "legal" for use with Amber turn but now trying to use Red Turn on same wiring, Worse in same small light fixture.
Even ignoring legal issues, Both red stop and turn lights on GT wiring in same fixture on the highway is a very good way to wreck the car.
If the jumper fix is done then Red turn/brake should be safe, pass most places and cops should not bother him.
Trailer adapter was never needed for this. Just the jumper at C500 will reprogram the car to work Red turn/stop light.

DOT Approved?
My guess the Corvette DOT "SAE codes" molded on the lens is IST or ISTA for the one w/ LED and R or RA for backup light. Dim Ring should pass as Taillight(T) and Bright Side Bulb should pass as turn/hazard(I) and stop(S). Should for both because he added LED. If that fixture has A then technically the ring is illegal. (Ring etc directly under reflector but most won't bother.)
Before you ask... backup up = R and reflector = A. The rest should be: year mold was design/made, maker of part, and GM code for model line the lamp was design for.
SAE codes are standard worldwide. See NHTSA Truck_Bus_MPV Poster

Fact is DOT/NHTSA does NOT approve anything. They only test when whatever has problem for investigating a Recall.
NHTSA did order APC and other to recall many illegal "Altezza-style" lights. see http://fmvss108.tripod.com/ if needed you have to search NHTSA of new links for Recall info.
Some Fools won't care until they have problem get thru inspections, cops stopping them, or dealing insurance/sued after a wreck. Many will whine to the planet and they did nothing wrong, Cops hate ___, etc.

(Edit to add small fixture)

[This message has been edited by theogre (edited 10-07-2015).]