Topic: Another interior light question.
in Forum: C3 Electrical
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Looking at the 72 electrical diagram it shows the following on the Orange wire Circuit.
R Courtesy
Cigar Lighter
Clock
R Court (Probably LH)
Rear Compartment ( I think is an Option for convertible)
Glove Box Light
does not show a dome light
Hopefully someone with a 72 could verify what lights come on in their cars when doors or Headlight Sw turned will come on.
I have a 77 which is slightly different I wish I was near to help you
Here is the courtesy light bulb
|UPDATED|7/30/2013 5:59:10 PM (AZT)|/UPDATED|
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Man I feel like a moron.
The needed lights are listed in my owners manual. So no problems there.
No matter what I do there is power to both the orange and white wires. Always. door open or closed. engine on or off. Except in the rear storage area. That one seems right. One contact hot and the other cold. I just need a #90 light to be sure. I would think both should be cold unless the door is open though.
In the foot wells I removed one socket and the other has no bulb. Still power in both wires. So corrosion in the sockets is not the problem.
I'm tempted to buy new switches to see if that works. If it doesn't I'm not sure where to turn. I know so little about vette electronics its embarrassing. I'd rather install a dozen steering boxes. Smile...
It seems I must have a bad light switch or bad door switches. When I installed the carpet there were no wires dangling from the switches and nothing looked odd. I do think its strange that two of the sockets were empty when I took delivery and the other burned out.
Bubba couldn't fix it either!
Hang in their that's why I tried to make the simplified diagram. The Orange wire should have power on them all the time from the courtesy light fuse.
you need a ground on any of the white wires to turn on the lights. Their should not be power on them with the headlight sw turned CCW that should make the wht wires grounded
you problem appears to be in the ground circuit Wht wires.
Do you know if the 72 had the delay timer for the courtesy lights if so bubba could have messed something up trying to bypass it I believe it would be located behind the clove box.
Ok time to buckle down and figure this out...first off do you have a DVOM? If not run to harbor freight and pick one up for 10$. Check what the actual voltage is at each of the wires...is it battery voltage on each one?...attach the black lead to a good ground like the battery itself...just clip a wire to the battery ground cable and run it out of the box to the front seat...if you know the voltage on those wires you'll have the answer to the problem. Post it up and we will fix this thing.
My first parade at Carlisle 2010
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
If there are bulbs in the sockets, and you are checking voltage with the door open, you WILL have voltage on the white wire IF....the white wire is NOT going to ground, as in, the wire is loose somewhere, or the pin switches are not making good grounds.
With a bulb in the socket, run a ground wire directly to the socket(to the white wire), and see if the bulb lights up. Bet it does. If so, then your mission, should you decide to accept it, is to find out where the ground circuit is open. 
Joel Adams
C3VR Lifetime Member #56 
My Link 
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Dang it Joel!! I wanted to show him that..lol...using the wire I said to use from the battery for a ground..but that was supposed to be my next post. You crack me up.
My first parade at Carlisle 2010
Okay.
One socket is completely removed no bulb, no socket. Just dangly wires.
The other socket has good bulb. ( I tested it.)
With bulb in socket grounded white wire in socket and we got light. With bulb in socket I grounded dangling white wire and I got light again. So the white wire is intact. Right? Now what? Pin switches bad? I don't see a delay installed but I could be missing something. Thanks guys.
Almost there! Ok this is the fun part....testing.. using the diagram from above you have power coming in on one wire which is good....the other wire is the ground. .this is where the meter kicks in. Put the red lead on the suspected ground wire, open the drivers door and hook the black lead to the ground wire from the battery that you ran up to the front seat...now set your meter to volts...dc volts...and it should read a very low number....0.02 or less...if it doesn't, which I suspect it will read random high numbers...open the passengers door and see if you get the low number...this may work since the rear interior light works...if it does then remove the door switch on the drivers side and hook the red lead to it as well....if you get the low number then the wire is ok and the switch ground is not good or the switch isn't working...if you don't get the low number then the ground wire from the bulb socket to the switch ground is open...see...easy stuff...im me if you need me to talk you thru this.
My first parade at Carlisle 2010
yostusota said: Almost there! Ok this is the fun part....testing.. using the diagram from above you have power coming in on one wire which is good....the other wire is the ground. .this is where the meter kicks in. Put the red lead on the suspected ground wire, open the drivers door and hook the black lead to the ground wire from the battery that you ran up to the front seat...now set your meter to volts...dc volts...and it should read a very low number....0.02 or less...if it doesn't, which I suspect it will read random high numbers...open the passengers door and see if you get the low number...this may work since the rear interior light works...if it does then remove the door switch on the drivers side and hook the red lead to it as well....if you get the low number then the wire is ok and the switch ground is not good or the switch isn't working...if you don't get the low number then the ground wire from the bulb socket to the switch ground is open...see...easy stuff...im me if you need me to talk you thru this.
Thank you so much! I do have a multimeter though, as luck would have it, the 9v battery is dead so I get to buy another before I can do the testing. I'm stuck with going to a birthday party tonight with fine seafood and wine... darn it. I gotta drink great wine tonight.
Anyway. Just one more tidbit for you. I ran the ground to the housing surrounding each of the pin switches to see if the light would go on. Nope. Nuthin. I'm really starting to think the pin switches are either bad or they're not making adequate contact with the bird cage.
Anyway, I truly appreciate your instructions. I'm accustomed to being something of an expert in my field and it is both humbling and exciting to be learning about this old Vette. People like you make it a lot more fun because I don't feel like the Lone Ranger.
This old Vette was pretty badly mistreated as of late. It is a convertible but spent some time being stored outdoors. Ouch! SO the seats were horrible and the carpet was worse. Mouse nest in the jack compartment. Lacquer checked paint... looked like I expect to look in another 30 years. 
Bad brake booster. Terrible door panels. Gauge bezel scratched and paint falling off. Door hardware scratched and worn. All emblems faded and worn. No courtesy lights working but the instrument panel lights do work. Clock, of course, not working. Goodyear Eagle tires that were rotting. Steering box that was beyond shot. You didn't drive this car... you influenced it! Shocks? Right. Cancer in the windshield header. That's the bad news.
Bad brake booster. Terrible door panels. Gauge bezel scratched and paint falling off. Door hardware scratched and worn. All emblems faded and worn. No courtesy lights working but the instrument panel lights do work. Clock, of course, not working. Goodyear Eagle tires that were rotting. Steering box that was beyond shot. You didn't drive this car... you influenced it! Shocks? Right. Cancer in the windshield header. That's the bad news.Good news? The prior owner was into engines and trannies. So the engine was rebuilt 5,000 miles ago and it runs like a top. Almost no vibration at all. But snaps your head back when it hits 2,000 rpm. Supposedly this old 350 develops 325 to 350 HP at the wheels. I believe it. The TH 400 tranny is solid and he even put in a tranny pan with cooling tubes. It is a fun car to drive.
The interior now looks and smells new. New Cooper Cobra tires. New shocks. New brake booster and master cylinder. New steering box. New seat covers and foam. New carpet. Reconditioned gauge bezel and door hardware. Running low on cash but the paint job and a little body work is coming. Then it's on to the long picking away at it phase. That will be my retirement activity.
I can do most of this work. But the electrical is something that dumbfounds me and always did. Even when I was doing tune ups and brake jobs back in the 70's the electrical was something we contracted out. So I'm actually excited to learn about it. Thanks for helping!
in Forum: C3 Electrical
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