Burb Backup Light Circuit - The 1947 - Present Chevrolet & GMC Truck Message Board Network

67 Burb · 08-09-2014, 03:44 PM

My 67 Burb originally had a 4 speed manual and now has a TH350 with (newer) column shift. I believe that the B/U light switch was on the transmission originally.

When I recently installed a new ignition switch, I ran a wire from there to the B/U light switch on the column (as well as wiring in the neutral safety switch).

My question is: Where does the wire run? I found part of the B/U wire on the right side behind the spare tire. How does it get from there to the dash?

Oldtruckfanatic · 08-09-2014, 04:26 PM

Its in the tail light harness On the automatic and column shift trucks. The four wires from the firewall running back that look like a trailer harness. On a trailer harness the 4th wire is white And Iits a ground. On our trucks its light green I believe. Brown= tail dark green= right turn/stop Yellow = left turn/stop and light green = back up lights. The light housings are grounded through the body. Im trying to remember how the floor shift manual trucks got the the power through the switch but its eluding me at the moment.

Bigdav160 · 08-09-2014, 04:32 PM

I'll check mine.I don't think the wires run through the firewall like the trucks.

OK, I just looked at mine. Since my Suburban is automatic is might be different however, the wiring going to the rear lights appears to enter the drivers A pillar just behind the left A/C duct.

It runs back along the roof rail and comes down the D pillar.

Oldtruckfanatic · 08-09-2014, 04:51 PM

Im not too familiar with suburbans but it wont matter where the harness is run. All that wire does is go from the fuse box to the switch and from the switch to the backup lights usually via the tail light harness. On automatics the switch is on the column and on floor shift manuals its on the transmission so there will likely be a plug underneath that doesnt go anywhere that will need a jumper or splice to complete the circuit after you redirect the power through the column switch. unless its cut off.

Oldtruckfanatic · 08-09-2014, 05:01 PM

If You already ran power into the b/u light switch then all you need to do now if there are 4 wires in your tail light harness is figure out which is the b/u light wire and splice your switch output into it. Its pretty easy to test by running a jumper to 12v power and checking to see if the lights come on. If they dont you can probe the center pin to verify power at the light socket with a test light.

Oldtruckfanatic · 08-09-2014, 05:12 PM

Sorry bigdav thanks for the clarification. I was so busy editing my typos ( I hate touch screen phones) I didnt see that you confirmed the harness location. Awesome info!

Bigdav160 · 08-09-2014, 05:19 PM

For the OP

67 Burb · 08-11-2014, 11:41 AM

Thanks for the info. I would like to run the circuit through the fuse panel, so I also have to find where the wire is that will go from there to the switch. I looked under the Burb, but couldn't find any wires that would have gone to the switch on the tranny. They should have passed through the bulkhead connector, I would think. ???

Bigdav160 · 08-11-2014, 04:16 PM

Quote:

They should have passed through the bulkhead connector, I would think. ???

Yes, service manual says light green and dark green wires in the middle of the bulkhead connector

67 Burb · 08-11-2014, 04:24 PM

Quote:

Originally Posted by Bigdav160

Yes, service manual says light green and dark green wires in the middle of the bulkhead connector

Thanks Bigdav

08-09-2014, 03:44 PM	#1
67 Burb Registered User Join Date: Dec 2011 Location: Brandon, Manitoba, Canada Posts: 548	Burb Backup Light Circuit My 67 Burb originally had a 4 speed manual and now has a TH350 with (newer) column shift. I believe that the B/U light switch was on the transmission originally. When I recently installed a new ignition switch, I ran a wire from there to the B/U light switch on the column (as well as wiring in the neutral safety switch). My question is: Where does the wire run? I found part of the B/U wire on the right side behind the spare tire. How does it get from there to the dash? __________________ Bob 1967 2wd Burb, 350/TH350, 3.73 posi

08-09-2014, 04:26 PM	#2
Oldtruckfanatic Truck junkie Join Date: May 2006 Location: Reno NV Posts: 697	Re: Burb Backup Light Circuit Its in the tail light harness On the automatic and column shift trucks. The four wires from the firewall running back that look like a trailer harness. On a trailer harness the 4th wire is white And Iits a ground. On our trucks its light green I believe. Brown= tail dark green= right turn/stop Yellow = left turn/stop and light green = back up lights. The light housings are grounded through the body. Im trying to remember how the floor shift manual trucks got the the power through the switch but its eluding me at the moment. Last edited by Oldtruckfanatic; 08-09-2014 at 04:38 PM.

08-09-2014, 04:32 PM	#3
Bigdav160 Registered User Join Date: Apr 2011 Location: Klein Texas Posts: 3,852	Re: Burb Backup Light Circuit I'll check mine.I don't think the wires run through the firewall like the trucks. OK, I just looked at mine. Since my Suburban is automatic is might be different however, the wiring going to the rear lights appears to enter the drivers A pillar just behind the left A/C duct. It runs back along the roof rail and comes down the D pillar. __________________ My Classics: '72 K20 Suburban + '65 Dodge Town Wagon '72 Corvette Roadster +'67 Corvette Roadster '73 Z-28 Camaro '63 Ford SWB Uni Pickup '50 Ford Coupe Last edited by Bigdav160; 08-09-2014 at 04:52 PM.

08-09-2014, 04:51 PM	#4
Oldtruckfanatic Truck junkie Join Date: May 2006 Location: Reno NV Posts: 697	Re: Burb Backup Light Circuit Im not too familiar with suburbans but it wont matter where the harness is run. All that wire does is go from the fuse box to the switch and from the switch to the backup lights usually via the tail light harness. On automatics the switch is on the column and on floor shift manuals its on the transmission so there will likely be a plug underneath that doesnt go anywhere that will need a jumper or splice to complete the circuit after you redirect the power through the column switch. unless its cut off.

08-09-2014, 05:01 PM	#5
Oldtruckfanatic Truck junkie Join Date: May 2006 Location: Reno NV Posts: 697	Re: Burb Backup Light Circuit If You already ran power into the b/u light switch then all you need to do now if there are 4 wires in your tail light harness is figure out which is the b/u light wire and splice your switch output into it. Its pretty easy to test by running a jumper to 12v power and checking to see if the lights come on. If they dont you can probe the center pin to verify power at the light socket with a test light.

08-09-2014, 05:12 PM	#6
Oldtruckfanatic Truck junkie Join Date: May 2006 Location: Reno NV Posts: 697	Re: Burb Backup Light Circuit Sorry bigdav thanks for the clarification. I was so busy editing my typos ( I hate touch screen phones) I didnt see that you confirmed the harness location. Awesome info! Last edited by Oldtruckfanatic; 08-09-2014 at 05:18 PM.

08-09-2014, 05:19 PM	#7
Bigdav160 Registered User Join Date: Apr 2011 Location: Klein Texas Posts: 3,852	Re: Burb Backup Light Circuit For the OP Attached Images __________________ My Classics: '72 K20 Suburban + '65 Dodge Town Wagon '72 Corvette Roadster +'67 Corvette Roadster '73 Z-28 Camaro '63 Ford SWB Uni Pickup '50 Ford Coupe

08-11-2014, 11:41 AM	#8
67 Burb Registered User Join Date: Dec 2011 Location: Brandon, Manitoba, Canada Posts: 548	Re: Burb Backup Light Circuit Thanks for the info. I would like to run the circuit through the fuse panel, so I also have to find where the wire is that will go from there to the switch. I looked under the Burb, but couldn't find any wires that would have gone to the switch on the tranny. They should have passed through the bulkhead connector, I would think. ??? __________________ Bob 1967 2wd Burb, 350/TH350, 3.73 posi



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