Installed CorvetteMods interior LED upgrade kit, DRL's and reverse lights finally.

Ordered resistors with the DRL's but haven't installed yet as I'm considering mounting the resistors on the taillights instead of the DRL's simply because there is more room to splice into the harness in the rear versus the front.

My thought is that the resistance issue is per side and that it shouldn't matter if the resistors are placed on the front or the rear. Has anyone done this as well or can a resident electrical wonk confirm that to be correct?

Additionally, is the analog flasher on the C6 part of the BCM or is it easily located/replacable with a digital unit that would eliminate the need to install inline resistors at all? If so does someone have a brandname and part # of the digital replacement unit?

UPDATE:
Installed resistors, mounting them next to each of the existing OEM lo-beam ballasts. Ran the ground wires to the OEM ground lug instead of splicing to eliminate splicing the ground on the OEM DRL harness. I'm pretty OCD about wiring/cabling so all connectors cables soldered and shrink-tubed where possible. Mounted with 3M moulding tape as I'm not concerned about the resistors getting too hot as they only get current while the turn signals are activated.


Installed the front LED markers in the existing clear front lenses even though Neal from corvettemods.com warned me that the bulbs would not fit without modification. Test fit confirmed the bulbs are too long in the OEM plugs to fit within the clear marker assemblies. Its not the length that has to be modified however, its the rounded plastic portion of the bulb base on both sides that has to be notched to permit the bulb to slide all the way down into the socket. The plastic bulb base is fairly soft and easily notched with a razor blade.

The remainder of the LED interior kit installation is simple plug/play with the exception of the rear cargo hatch 6-led lights which require bending the copper housing slightly because the OEM bulb contact ends are square and the replcament LED assembly contact ends are triangular. Since the triangular ends don't fit onto the OEM square contact tabs you have to bend the assembly inward at an angle so the assembly will sit on both OEM socket contact tangs.

Photos of resistor mount and ground location:

 

I didn't install the resistors either, and thought of installing them on the taillight but thought the resistors might get even hotter that way..Ed

 

Installing them on the rear won't solve the front hyperflash, fyi

 

You need the resistors in both the front and rear if you use LED's in both the front and rear. The computer monitors the bulb current in all four locations for the signal lights and will hyper-flash if the current is low indicating a burnt out bulb. Since the LED's draw very little current, the computer will interpret that as a burnt out bulb hence the use of the resistors at any location that a LED bulb is used.

 

i have rear leds, they come with ballasts for hyper flash, and switchback DRL's. I ran wires to the engine compartment through a hole already near where the DRL's go. It was a great spot and i put 1100 degree radiant/500 degree contact tape under the resistors and used a long screw to suspend them about 3/4 of an inch off the wall itself to get better air flow. I since removed them because i smelled burning a few times and didn't want problems, but i later found out the smell was probably just the resistors being new and burning off whatever it was coated with... I have yet to reinstall them out of laziness but i really don't mind the hyper flash as long as it doesn't damage the other leds.... good luck, and as stated already having the resistors on the back does nothing to solve front DRL's, you need one resistor on each DRL....

 

I purchased all the same and like you i haven't installed the resistors yet. I know I need to because not only do I get the hyper flash (which I don't mind) but my right side DLR randomly shuts off.

Do you think the resistors will fix this

 

My opinion,no. Am I an expert on this, no, but common sense rationing makes me think that the bulb is going out for a reason that tricking the bcm to think a bulb is there won't fix... That's all resistors do, takes enough power as a reg bulb so the bcm thinks a bulb is there. Should have no effect on a bulb only working sometimes...

 

Bulbs are brand new. I'm going to switch left and right to see if its a bad bulb. Got them from corvette mods so if its a bad bulb they will replace it. Probably will turn out to be that I didn't put it in tight enough

 

Resistors should be mounted on something metal if possible to absorb heat.

 

See updated top post.

Unless you're the type to drive around with your turn signals on constantly the DRL resistors will never get hot enough to make a differences as they only receive current when the turn signal is actually flashing.

 

Do you have DRLs and are they functioning? You cannot tell with the car sitting still. engine running, even with the parking brake off, as I recall. I could be wrong on that.

If you do, the turn signals are on ALL THE TIME, asi it is the turn signal filaments that are used for the DRLs. I found this out by staring at the electrical schematics in the FSM for............more than a little while. Worse, the DRLs and turn signals are controled by software (logic) in the BCM. Good luck changing that!!

I tried to put the switchbacks in my '05 but gave up as they would not function correctly (even without the resistors) and then reading the warnings and instructions on the resistor packaging..."Not suitable for DRLs" was the final straw. They run really really hot.

 

Where did you order them from? We've been selling functioning units for years!

 

The OEM bulbs are dual filament, one filament reserved for DRL function and the second filament reserved for turn signal flash. On C6's the turn-signal filament is powered by the Blue/White lead on the DRL harness. That lead only gets 12v when the turn signals are flashing, which explains why the resistors never have time to get very hot as they only intermittingly reaceive voltage in parallel to the LED bulb for the duration of your turn signals being active.

From what you describe, it sounds like you might have spliced into the wrong hot lead on your DRL harness for the resistor.

I will tell you that the resistors I received from Neal had no such warning about acceptability for DRL use. The only label on the unit at all described the wattage and resistance.

 

I am not talking about what I did or did not do on the car. I never got to the point of slicing into wires. I disagree with your assessment of how the filaments are used for turn signals, parking lights and DRLs. Of course, my comments are for a 2005 and it is possible that GM made a change with later cars.

What I did do first was read the wiring diagram(s) in the Factory Manuals to determine how the DRLs, parking lights and turn signals work. According to the wiring diagram(s), the BCM uses the same filament for both functions. The other filament is used solely for parking lights only.

This does not change with LEDs. The BCM will still send current down the same wires regardless of bulb type.

All I'm suggesting is you should check to ensure that the resistors will not be seeing current when the DRLs are on; especially with where you have them mounted. Headlight hoousings and ballasts are not cheap!! I think it makes sense to be doubly sure you will not have a problem.

 

The DRL's and turn signals use the same brighter filament in the OEM bulb. In a white/amber switchback LED this is the amber 'side'.

The running and parking lights use the dimmer filament. In a white/amber switchback LED this is the white 'side'.

The switch part of the white/amber switchback LED switches off the white 'side' when the turn signals (or DRL's) are used, so you can see the amber 'side' of the LED. If the white 'side' was not switched off, it would wash out/overpower the amber 'side'.

This switch is also what can fail when it is continuously powered on in DRL mode. Some manufacturers warn not to use switchback LED's for DRL's because of this.

As long as you don't use your DRL's the front load resisters will not heat up too much. But you still should mount them so they won't melt/damage anything.

The front and rear lighting/turn signal circuits are completely separate and what you do at one end of the car has no effect on the other.

 

There are two circuits for the DRL/turn signal/parking lights.

During the daytime the DRL's use the same circuit as the turn signals and will get really hot as the load resistors are drawing current 100% of the time. The computer makes/breaks that circuit to flash the turn signals when the headlights are off and DRL's on on. When the headlights are on, the DRL's are on the second circuit(same as the parking lights) and the load resistors only draw current when the turn signal are actually flashing, thus don't get as hot. When you activate the turn signal, the computer then switches the voltage from the second circuit to the first circuit so the turn signal flash bright.

If you don't want the load resistors melting everything around them, then you need to either turn the DRL's off during the daytime, or run with your headlight on during the daytime, or mount the load resistors where they won't melt the surrounding plastic, etc.


I went to a lot of trouble to ensure my load resistors didn't melt my car.

 

[QUOTE=FireRoc;1582905216]I am not talking about what I did or did not do on the car. I never got to the point of slicing into wires. I disagree with your assessment of how the filaments are used for turn signals, parking lights and DRLs. Of course, my comments are for a 2005 and it is possible that GM made a change with later cars.

What I did do first was read the wiring diagram(s) in the Factory Manuals to determine how the DRLs, parking lights and turn signals work. According to the wiring diagram(s), the BCM uses the same filament for both functions. The other filament is used solely for parking lights only.

This does not change with LEDs. The BCM will still send current down the same wires regardless of bulb type. QUOTE



I have not checked the C6 wiring diagrams, but what FireRoc says here is definitely correct for the C5. This means the resistor will dissipate a lot of power when the DRL's ar on during normal driving. The second filament is for the parking lights.

 

This is correct for all C6's. The DRL's use the signal light filament in the day and therefore the resistors will draw current all the time that they are on.

When the headlights are on, the DRL's use the secondary filament and therefore the resistors draw current only when the signal lights are used.

 

This is absolutely correct. And if you don't think so, grab that resistor when the headlights are off and see if you don't come away with a deep branding mark on your hand. Hsssssssss! I suspended my resistors in mid-air with about 8 inches of steel wire, attaching to those clips or whatever they are on the back of the parking light, with the other end to the resistor (of course). It just hangs there, far away from anything "melty".

It takes a bit of thinking to understand how the DRLs are powered differently when the headlights are ON vs. when they're OFF.

 

OK, after reading all of the comments I've no choice but come to the conclusion that some of the people who posted in this thread fall into one or both of the following two categories:
A Have zero personal experience installing DRL's and resistors on a C6.
B Have no basic understanding of how a dual filament turn signal / running light bulb works.

I can tell you that the following observations are the result of my installation and I re-verified the various scenarios this morning to confirm. I tested the scenarios with no turn signal first for obvious reasons.

My results of a successful DRL/resistor installation on a C6 Corvette are as follows:
1. All lights off (DRL's, markers, headlights, etc) = no current to either resistor
2. DRL's on solid with headlights off = no current to either resistor
3. DRL's on solid with headlights on = no current to either resistor
4. DRL's on solid with headlights off and turn signals activated = intermittent current to one resistor
5. DRL's on solid with headlights on and turn signals activated = intermittent current to one resistor

Additionally as you can see from the attached video there is no hyperflash and I can confrim that the resistors are working as designed when the turn signals are activated as they get warm to the touch quickly.

As I stated previously, when correctly installed the resistors only receive current when the turn signals are activated. Anyone who claims otherwise has either never actually performed the installation themselves or tapped the wrong hot lead on the DRL bulb socket harness that leads to one side of for the resistor (the other side of the resistor goes to ground obviously).