Help with Electrical Problem - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Already Gone** · 06-10-2007, 12:53 PM

I am changing over from my step to a new sport bumper. As you can see in the pic the po had installed a set of running lights just above the bumper. When I started to check things out and undo the wiring yesyerday it looked straight forward. Those running lights were wired along with the license plate lights so that when you put on your park or headlites they came on. There was also a big ground strap from one of the bumper brackest to a bolt in the bar the running lights were on. I found the positive wire coming out of the factory tail/brake running light harness which the po had used to power the running lights and license lights. So I disconnected all the running lights and license lights left the ground strap intact. I thought I'd make sure I had power and when I pulled my park lights on I had no taillights /brake lights or factory running lights on the truck and when I checked with the test light I have no power from the wire that was powering the rear running lights and license lights. Anyone got any ideas what could be wrong? I'm thinking some kind of ground problem

**Already Gone** · 06-10-2007, 01:43 PM

ttt

jhow66 · 06-10-2007, 02:49 PM

Brown wire will be the hot wire when parking lights or headlights are on. Take your test light to this wire and ground.

Longhorn Man · 06-10-2007, 04:00 PM

Make sure your test light is grounded good... if you get no reading, then you have no power.
The lights weren't on why you were cutting them out were they? (blown fuse) or any bare spots not taped up yet? (fuse)

**truckdude239** · 06-10-2007, 04:22 PM

check the grounds mine didn't work and it was where the buckets contact the body ont he backside they are self grounding if you dont have a good ground no workl sand the buckets and body put back in and try thats what i did

**John Fabris** · 06-10-2007, 04:33 PM

Check your fuses?

lbpd719 · 06-10-2007, 06:51 PM

make sure you didn't reverse one of the lights in the bucket too. Fuse would be first, but if you reversed a set, bang, blown fuse.

Disconnect EVERYTHING and check the fuse, then bring the lights up one at a time, checking the wires for any brakes or potential runs to ground.

also make sure you didn't reverse the license plate lamp.. they don't always hook up like you think they would..

Good luck..

**Already Gone** · 06-10-2007, 09:31 PM

Firstly thanks for your help and suggestions guys, I always appreciate the help I get on here. Now for the rest of the story.. Seeing I wasn't having any luck with the electrical I thought I might as well stick the new sport bumper on the truck while I had some time and worry about the electrical later. Okay so me and my beautiful lady grunt and twist and push and pull and we get the new bumper installed. I deciede taht is enough for today and jump in the truck to drive it around to the front of the house. When I get there my wife is satnding on the curb waiting for me and says" Idont know if I should tell you this or not, but your brake lights are working" I shook my head and pulled the headlite switch to the opark poition and lo and behold I had all my lights I didnt have an hour earlier. I did nothing electrical to change anything, all I did was change bumpers. With the old bumper removed from the truck ,no lights, with the new bumper installed I have lights..

Longhorn Man · 06-10-2007, 09:31 PM

you can't reverse the wires on the lic plate light, it only has one wire.
And reversing the wires on the tail lights would just make them bright all the time.

Longhorn Man · 06-10-2007, 09:40 PM

Add a ground to the bed... my first truck did this. My tail lights would all go out, then all I'd have to do is lean on the rear bumper, and they'd light up.

**kwmech** · 06-10-2007, 10:00 PM

Pink?

**Already Gone** · 06-11-2007, 04:56 PM

Quote:

Originally Posted by kwmech

Pink?

Oh yea !!!!!!!

**Already Gone** · 06-11-2007, 01:45 AM

Quote:

Originally Posted by Longhorn Man

Add a ground to the bed... my first truck did this. My tail lights would all go out, then all I'd have to do is lean on the rear bumper, and they'd light up.

Do you know why it did that? What does the bumper have to do with it?

jhow66 · 06-11-2007, 10:58 AM

Quote:

Originally Posted by Already Gone

Do you know why it did that? What does the bumper have to do with it?

Nothing. All he was doing was making some part of the bed make a ground to the frame. When ground was made, lights would come on. Ground your bed to the frame with a jumper wire if this is your problem.

cdowns · 06-11-2007, 11:06 AM

they came from the factory with a grounding strap between the bed and the frame crossmember for a reason

06-10-2007, 12:53 PM	#1
Already Gone 70+ ( Old Skool Club ) Join Date: Nov 2003 Location: Saskatoon, Saskatchewan ,Canada Posts: 9,161	Help with Electrical Problem I am changing over from my step to a new sport bumper. As you can see in the pic the po had installed a set of running lights just above the bumper. When I started to check things out and undo the wiring yesyerday it looked straight forward. Those running lights were wired along with the license plate lights so that when you put on your park or headlites they came on. There was also a big ground strap from one of the bumper brackest to a bolt in the bar the running lights were on. I found the positive wire coming out of the factory tail/brake running light harness which the po had used to power the running lights and license lights. So I disconnected all the running lights and license lights left the ground strap intact. I thought I'd make sure I had power and when I pulled my park lights on I had no taillights /brake lights or factory running lights on the truck and when I checked with the test light I have no power from the wire that was powering the rear running lights and license lights. Anyone got any ideas what could be wrong? I'm thinking some kind of ground problem Attached Images __________________ 1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021

06-10-2007, 01:43 PM	#2
Already Gone 70+ ( Old Skool Club ) Join Date: Nov 2003 Location: Saskatoon, Saskatchewan ,Canada Posts: 9,161	Re: Help with Electrical Problem ttt __________________ 1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021

06-10-2007, 02:49 PM	#3
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Re: Help with Electrical Problem Brown wire will be the hot wire when parking lights or headlights are on. Take your test light to this wire and ground. __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

06-10-2007, 04:00 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Help with Electrical Problem Make sure your test light is grounded good... if you get no reading, then you have no power. The lights weren't on why you were cutting them out were they? (blown fuse) or any bare spots not taped up yet? (fuse)

06-10-2007, 04:22 PM	#5
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,238	Re: Help with Electrical Problem check the grounds mine didn't work and it was where the buckets contact the body ont he backside they are self grounding if you dont have a good ground no workl sand the buckets and body put back in and try thats what i did __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

06-10-2007, 04:33 PM	#6
John Fabris TOTY 2006 Join Date: Dec 1999 Location: Magalia CA USA Posts: 2,270	Re: Help with Electrical Problem Check your fuses? __________________ John Fabris 67 C10 SWB

06-10-2007, 06:51 PM	#7
lbpd719 Zappaphile! Join Date: Apr 2007 Location: Los Banos, California Posts: 228	Re: Help with Electrical Problem make sure you didn't reverse one of the lights in the bucket too. Fuse would be first, but if you reversed a set, bang, blown fuse. Disconnect EVERYTHING and check the fuse, then bring the lights up one at a time, checking the wires for any brakes or potential runs to ground. also make sure you didn't reverse the license plate lamp.. they don't always hook up like you think they would.. Good luck.. __________________ 1969 C20 LWB Camper Special - The Beater.. 1998 Cheyenne V6 - 4/6 Drop - For The Son

06-10-2007, 09:31 PM	#8
Already Gone 70+ ( Old Skool Club ) Join Date: Nov 2003 Location: Saskatoon, Saskatchewan ,Canada Posts: 9,161	Re: Help with Electrical Problem Firstly thanks for your help and suggestions guys, I always appreciate the help I get on here. Now for the rest of the story.. Seeing I wasn't having any luck with the electrical I thought I might as well stick the new sport bumper on the truck while I had some time and worry about the electrical later. Okay so me and my beautiful lady grunt and twist and push and pull and we get the new bumper installed. I deciede taht is enough for today and jump in the truck to drive it around to the front of the house. When I get there my wife is satnding on the curb waiting for me and says" Idont know if I should tell you this or not, but your brake lights are working" I shook my head and pulled the headlite switch to the opark poition and lo and behold I had all my lights I didnt have an hour earlier. I did nothing electrical to change anything, all I did was change bumpers. With the old bumper removed from the truck ,no lights, with the new bumper installed I have lights.. __________________ 1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021

06-10-2007, 09:31 PM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Help with Electrical Problem you can't reverse the wires on the lic plate light, it only has one wire. And reversing the wires on the tail lights would just make them bright all the time.

06-10-2007, 09:40 PM	#10
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Help with Electrical Problem Add a ground to the bed... my first truck did this. My tail lights would all go out, then all I'd have to do is lean on the rear bumper, and they'd light up.

06-10-2007, 10:00 PM	#11
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,717	Re: Help with Electrical Problem Pink?

06-11-2007, 11:06 AM	#15
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Help with Electrical Problem they came from the factory with a grounding strap between the bed and the frame crossmember for a reason __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

Thread Tools
Show Printable Version Email this Page
Display Modes
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.