C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

forward light wiring harness issues

Thread Tools
 
Search this Thread
 
Old 06-05-2014, 05:45 PM
  #1  
Gsmit72
Navigator
Thread Starter
 
Gsmit72's Avatar
 
Member Since: Jun 2014
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Default forward light wiring harness issues

I have a 72 project corvette. I am working on the forward wiring harness. The headlights work. The passenger side parking or running lights do not. Turn signals are intermittent, everything flashes when hazards are on. Basically it is a mess. I checked the wiring diagram and it seems like it is run correctly. I have checked with the volt meter and I have power at the light. I replaced all of the bulbs re spliced anything that was done before and changed the flasher module. Could any of my issues be in the headlight switch or turn signal switch? Any ideas on where to start would be appreciated.

Gerrit
Old 06-05-2014, 07:10 PM
  #2  
DUB
Race Director
 
DUB's Avatar
 
Member Since: Apr 2009
Location: Charlotte NC
Posts: 19,294
Received 2,713 Likes on 2,321 Posts

Default

Gerrit,

WIRING 101 is in session:

GROUNDS!!!!! You can have power to all terminals and if you do not have a good ground...it will and will not work.

IF your headlights work on low beam and high beam....GREAT! DO THEY?

NOW...if your hazards are working (with the headlights off)...it is because it is "finding" a ground through the other filament in the bulb. This is because the taillight and turn signal bulbs have 2 filaments in them...BUT....they share a common ground...which is the brass socket on the bulb. SO....

You can have your turn signals working fine when the HEADLIGHTS are OFF....and this is because the running filaments in the bulbs are NOT being used...so the turn signals can be using them to operate and "find" a ground. BUT....the second you turn on your running lights...the turn signals DO NOT work.

I would be shocked that if your hazards work with the HEADLIGHTS OFF....still work with the HEADLIGHTS ON.

VERIFY that you have a ground where they are needed. A lot of times the black wire on the side of the socket can break and or the terminal looses connection. When checking these grounds...use you volt meter and touch the terminal inside the socket with the bulb out.

Let me know what you find.

DUB



Quick Reply: forward light wiring harness issues



All times are GMT -4. The time now is 05:58 PM.