spstack

Greetings,

I recently fixed the dim headlights on my vette and thought I could save people time and money by posting my fix here.

Issue on my car and likely all C2s (have not verified) is that the low beam headlights are not dedicated to just low beam. They also have a high beam filament.

Due to the wiring issues that are widely known, my low beam filament was only getting 11.5V vs 12.5V at the battery. At the same time, my high beam circuit was being fed about 3.5V so high beams are on but just very very dim.

For the most part, my high beams were working ok because all filaments on both lamps were getting about 11.5V.

However, low beams are more important to me and I did not want to adjust all lights down and just run on high.

So I opted to isolate the light into separate high and low beam functions. I did this by simply removing the high beam wiring/spade from the low beam connector/socket and wraping with black duck tape (to keep from shorting on anything). I then soldered a jumper wire from the low beam to high beam spades on the actual bulb.

This isolated the bulbs to act on their own circuit and effectively raised the voltage in each circuit and as an added bonus gave me 2 filaments burning in the low beam lamps which increased the brightness dramatically.

I then took it out at night and double check the adjustment of the individual bulb for both high and low and the work great. They are not new car bright, but they are very very drivable in both high and low.

I have attached a couple of pics of the finished product. I did not take pics prior but the low beam were so dim they were basically undrivable.

Hope this helps someone else.. much better route than messing with switches, grounds, alternators, etc. and mods are reversible and hidden inside the headlight bucket.

Cheers, Sean

Frankie the Fink

Adding relays accomplishes the same thing with the add'l advantage of keeping that large headlight current out of the dash switch.

spstack

Absolutely... thanks Frankie. I have used relays before for headlight wiring on other projects. However, I was looking for a solution that didn't require relays for my vette to keep everything as bone stock as possible.

Frankie the Fink

Hey - if it works, it works!
Relays can be a tad tricky to install and DO add an add'l point of failure in the headlight circuitry...

AZDoug

I made a relay harness that plugged into the existing harness, between the main body harness and each headlight set harness. It can be removed by simply unplugging it and plugging the factory harnesses back together. Of course, I had to run a big 8 ga wire up front to supply headlight power. The relays are zip tied to the metal supports under the nose piece. Unless you are looking for it, you would never know it is there


I sat down, drew it out, ordered the necessary parts and spent an hour or two soldering the relay harness together.

Doug

ChattanoogaJSB

Doug- would it be easy for you to outline exactly what you used and how you ran this? I'm interested! I have been considering the MAD wiring setup but yours could be a rewarding project, I'd rather "build myself" often times.


Thanks to the OP for this thread, while I was searching I came across it. Sorry to resurrect one a little older.

C-1 Generation 2

I did relays, a couple of bus bars and fusable links and bypassed the amp gauge a few weeks ago. Prior to doing that the headlight switch would be blinking my halogen when on high beam. Should I desire to add a sub and amp for my stereo I now have safe bus bars to power them up.
I used all parts from Mad Electrics.

ChattanoogaJSB

One more post on this, a simple thank you to the OP...I did this last night when I was finishing up the headlamp work, I tested it first with a temporary jumper and of course you were quite right- it's a noticeable difference! Thank you! I dig it.

Tiros

But now your low beam lamp doesn't light at all on high beam setting?

ChattanoogaJSB

True the low beam lamp cuts out when you switch to the high beams. The whole thing is easily reversible, nothing is cut in doing it- for now I'm glad to have the extra ooomph on the more-used low beam setting. I may eventually do the MAD wiring relay kit (it's so cheap!) to get more voltage and go back to stock. But I have to say this is a pretty nifty fix. I put on my Bubba hat when I did it....