lighting problem
Thread Starter
Safety Car
Joined: Oct 1999
Posts: 4,409
Likes: 1,280
From: Florida
lighting problem
Hi to all...I am stumped...it has been years since I have been forced to work on a C3, but now I have to...have been helping people for years with their wiring diagrams but now I need help...our latest edition (1978 SA) has the convenience package...no lights go on when I open a door...but they do when I turn the headlight switch counter-clockwise one click...all of the fuses are good...what gives?
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,573
Likes: 7,017
From: New Or-leens Loo-z-anna
Rookie questions:
Neither door will activate the lighting?
Are the door switches getting ground?
Is there some sort of OFF-timer/module in the circuit that could be faulty?
Loose ground wire in the door harness?
Sorry I can't give you an answer.
Neither door will activate the lighting?
Are the door switches getting ground?
Is there some sort of OFF-timer/module in the circuit that could be faulty?
Loose ground wire in the door harness?
Sorry I can't give you an answer.
Last edited by doorgunner; Aug 21, 2014 at 12:33 AM.
Melting Slicks
Joined: Mar 2008
Posts: 2,023
Likes: 6
From: Austin Tx
And to add to what has already beed said. The delay timer is a common source for a battery drain.
Here's a link to one for sale - http://www.corvettemods.com/78-82-C3...er_p_9589.html
I would first unscrew the door switches, and make sure that they are still connected - if there was an issue with the lights not going off in the past (like a bad timer), then a PO may have disconnected the wires from the door switches, thus keeping the door switch from activating the timer relay, but allowing the lights to be manually turned on at the headlight switch.
If the switches are still connected, or you connect them and the lights stay on, then I need to look at the timer relay.
Burning Brakes
Joined: Dec 2003
Posts: 974
Likes: 0
From: Boca Raton Florida
Papawana , it's chris the guy who sold you the car . I took out the timer which was located on the left side of the car underneath the dash because all the lights were staying on . When i purchased a new one and installed it , the lights still stayed on . At this point the courtesy timer is out of the car but I included a new one (orange box) when I sold you the car . The timer is usually the source of the lights on problem but not in this case . I hope someone can chime in and help . I left it that way because the lights still worked without the timer with no drain on the battery ..... 
Le Mans Master
Joined: Aug 2006
Posts: 7,421
Likes: 1,558
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
The timer was originally installed behind the lower passenger side dash.
You can bypass the timer module by connecting the two white wires at the module together.
If the lights go on and off as the door is opened and closed then the switches are good.
If the lights work properly, then now you can install the new module.
You can bypass the timer module by connecting the two white wires at the module together.
If the lights go on and off as the door is opened and closed then the switches are good.
If the lights work properly, then now you can install the new module.
Le Mans Master
Joined: Aug 2006
Posts: 7,421
Likes: 1,558
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Thread Starter
Safety Car
Joined: Oct 1999
Posts: 4,409
Likes: 1,280
From: Florida
problem
I talked to the previous owner...he had the timer control unplugged...he said the when plugged in the lights would not shut off...when unplugged the lights worked just fine...they do not now...he left me the timer control...the only bad wire I found was one of the glove box light wires was broken, now repaired
Last edited by papawana; Aug 24, 2014 at 11:15 AM. Reason: added info