Backup lights not working
03-04-2018, 02:19 PM
#1
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Thread Starter
Backup lights not working
Looking for advice on the best place to start searching for a break in the backup light circuit. I have power to the b/u switch, power out of it when car is in reverse. No power back at the bulb sockets verified with a test light. So I suspect a break between the switch and the back of the car.
Short of taking apart the dash, interior and harness, is there a weak spot in the circuit where most of the problems happen?
Short of taking apart the dash, interior and harness, is there a weak spot in the circuit where most of the problems happen?
03-04-2018, 02:35 PM
#2
Melting Slicks
What year is your car?? There should be a connector for the rear harness. Are the bulbs good?
Last edited by speedreed8; 03-04-2018 at 02:57 PM.
03-05-2018, 06:43 AM
#4
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mine was a bad ground at the socket but it was a 68. i would check under the door sill. its about halfway. you can keep probing the line that way systematically until you find it. good luck
03-05-2018, 12:13 PM
#5
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Power comes into the backup lamp switch on the pink/white wire, then goes out on the light green. It passes through two connections before it hits the lamps.. 1 is the firewall connection and the other is the front to rear harness connection.
So.. if you have power at the switch in/out, then go to the firewall connection and test it there... if you have it there then remove the right hand kick panel and you'll find the front to rear connection... then test it there as well. If you have power there then you possibly have a wiring issue between the front to rear connection to the rear lamps.
I'd also verify that you have a good ground at the laps... possibly before I tested anything else. Using your test lamp, check for power at the rear lamp by using another known ground. If you light up, then use the back wire as your test ground.
You can copy this schematic and paste it into any "paint" program... then you can trace out the circuit with the pen tool. Just right click on it, then select copy... open paint up, then paste it and save it as a JPG picture.
http://repairs.willcoxcorvette.com/w...y-complete.png
Willcox
So.. if you have power at the switch in/out, then go to the firewall connection and test it there... if you have it there then remove the right hand kick panel and you'll find the front to rear connection... then test it there as well. If you have power there then you possibly have a wiring issue between the front to rear connection to the rear lamps.
I'd also verify that you have a good ground at the laps... possibly before I tested anything else. Using your test lamp, check for power at the rear lamp by using another known ground. If you light up, then use the back wire as your test ground.
You can copy this schematic and paste it into any "paint" program... then you can trace out the circuit with the pen tool. Just right click on it, then select copy... open paint up, then paste it and save it as a JPG picture.
http://repairs.willcoxcorvette.com/w...y-complete.png
Willcox
Last edited by Willcox Corvette; 03-05-2018 at 12:15 PM.
03-07-2018, 07:34 AM
#7
Le Mans Master
Do you have a pointy test light, with a sharp enough test probe to poke through insulation? I have something like this, which is invaluable.
http://amzn.to/2Fl6zuv
You can use it to test along the circuit, anywhere you find the wire per the excellent Willcox diagram, and quickly determine where the break is before pulling any panels off the car.
That said, it's (almost) always a connector. Perhaps even inside the rear socket itself. Mine broke apart inside the socket itself, leaving just enough for intermittent lights, until I swapped out the sockets for repros.
http://amzn.to/2Fl6zuv
You can use it to test along the circuit, anywhere you find the wire per the excellent Willcox diagram, and quickly determine where the break is before pulling any panels off the car.
That said, it's (almost) always a connector. Perhaps even inside the rear socket itself. Mine broke apart inside the socket itself, leaving just enough for intermittent lights, until I swapped out the sockets for repros.
03-07-2018, 11:10 AM
#8
Advanced
Thread Starter
Do you have a pointy test light, with a sharp enough test probe to poke through insulation? I have something like this, which is invaluable.
http://amzn.to/2Fl6zuv
You can use it to test along the circuit, anywhere you find the wire per the excellent Willcox diagram, and quickly determine where the break is before pulling any panels off the car.
That said, it's (almost) always a connector. Perhaps even inside the rear socket itself. Mine broke apart inside the socket itself, leaving just enough for intermittent lights, until I swapped out the sockets for repros.
http://amzn.to/2Fl6zuv
You can use it to test along the circuit, anywhere you find the wire per the excellent Willcox diagram, and quickly determine where the break is before pulling any panels off the car.
That said, it's (almost) always a connector. Perhaps even inside the rear socket itself. Mine broke apart inside the socket itself, leaving just enough for intermittent lights, until I swapped out the sockets for repros.