Topic: Stupid electrical question
in Forum: C3 Electrical
Lifetime MemberModerator
Joel Adams
C3VR Lifetime Member #56 
My Link 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
The front side marker bulbs are 12 V. Bulb number either 168 or 194. The 194 is a touch brighter.
One side of the bulb connects to the turn signal. The other bulb contacts connects to the park light. (No Really)
When the park light is turned on, the side bulb becomes hot, and grounds through the turn signal, and stays on steady.
When the turn signal is on, the bulb grounds through the park lights. It now blinks with the turn signal.
When BOTH park and turn signal are on, the side bulb has a hot lead on each side, so it does not light. When the turn signal goes out, it comes on. So it blinks opposite of the turn signal.
It lights due to the fact that the amperage is very small compared to the other bulbs. There is enough resistance in the 194 bulb to allow enough current flow to light itself, but prevents enough current to light the park or turn signal lights. Somewhat of a neat little trick actually.
Lifetime MemberModerator
Most led lights that I'm aware of have to have some sort of "transformer"(for lack of a better word), to operate with the brake/park/turn sig. lights, due to the amperage diff. I would think just tying into the front/rear t.s. would be sufficient, even with a 'power pac/transformer' type set-up.
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
You should be able to go the the original front turn signal and connect the LED hot and ground to the original hot and ground. It should be fairly straight forward, and won't affect the side light. If the blinker now operates at the wrong speed, just replace it with a common heavy duty flasher.
I forgot to look at my diagrams for the rear window defog. I need to remember to do that.
Thanx for all the help yall
Glenn
This isn't going to help you right away, but I'm out working on my 78's rear defogger and the assemby manual just delivered from Corvette America has the actual enginering diagrams for my set up. Helped alot tracking the wiring. Highly recomended, and seems to be available for every year Vette. Also - since it's available used for my 78, I'm assuming it's also available for your 75 - an electrical troubleshooting manual. That has all the color codes of each wire in the car. Also helped me chase down the defogger wires.
