light fuse blows, where do i start? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

mustardjimmy71 · 07-01-2011, 12:06 PM

on my 71, when i pull the headlight button out 1 click the 20a fuse blows and i lose the associated lights. where do i start? 2nd click and i have headlights, high beams, and signals, reverse lights.

cdowns · 07-01-2011, 12:22 PM

a good place to start wood b by reading the board rules about double postings

Longhorn Man · 07-01-2011, 06:50 PM

look at the parking lights and the wires. If the harness has been hacked for a trailer plug, I'd start there.

Lee H · 07-01-2011, 10:28 PM

Check the grounds.
Posted via Mobile Device

BMERDOC · 07-01-2011, 10:59 PM

Have you done any work recently? Which 20A fuse blew? There are several easily acceible pics of the fuse box to help.
I'm still new to the details of these trucks but I'm growing stronger every day. Give us the details and some one here can help.
Quick diagnosis for someone who doesnt know a lot about electricity is this. Unplug the taillamp harness at the firewall. Its inside the cab and just above the gas pedal. Pull the light switch to section one, fuse blown? No, Your problem is in the tail lamp section. You have just eliminated everything on the fuse as a source. Plug the taillamp harness back in and unplug at the taillamp connector at the back of the bed (on the left when lookin at the back of the cab just behind the bumper). Retest, blown fuse, yes? Check the taillamp harness for a short to ground. If you initially unpluguged the connector underneath the dash and it did pop, do this. Go to the front connector at the firewall (to the right of the M/C) and unscrew it to unplug it. Retest circuit, blown fuse, no. Check the front harness for bare wire. Its not long and will take minutes to check. If you have a buddy and a small collection of spare fuses you can shake the harnesses to check for the short to ground.
These are quick directions for someone who can get around a truck. Again, if you supply more info I'm sure myself or another member would help you with a big smile. I love fixin things.

BMERDOC · 07-01-2011, 11:23 PM

Quote:

Originally Posted by BMERDOC

everything ***ELSE*** on the fuse as a source. Plug the taillamp harness back in and unplug at the taillamp connector at the back of the bed (on the left when lookin at the back of the cab just behind the bumper).

I can't edit for some reason. I guess I edit too much and my right has been revoked for some reason.

mustardjimmy71 · 07-02-2011, 02:28 AM

Quote:

Originally Posted by cdowns

a good place to start wood b by reading the board rules about double postings

well the electrical section gave me no results and a couple views so thanks for taking your head out of your... hat

bmerdoc, thanks ill crack a beer and try that in the morning

mustardjimmy71 · 07-02-2011, 08:29 PM

Thanks longhorn man and bmerdoc. I unplugged the harness in the rear and there was no blow. I noticed some wires tucked away and they had bare ends. must have been from trailer wireing. Some black tape fixed it up.

Still no help from the electrical section

BMERDOC · 07-02-2011, 08:42 PM

I'm glad we could help. I haven't been a member of a forum for a long time because of less than desireable members. I found you guys and have been extremely happy. I'll answer any question I think I may be able to help with. ENJOY THAT TRUCK!!!!

07-01-2011, 12:06 PM	#1
mustardjimmy71 toys'r'us Join Date: Nov 2010 Location: Penticton, BC, Canada Posts: 347	light fuse blows, where do i start? on my 71, when i pull the headlight button out 1 click the 20a fuse blows and i lose the associated lights. where do i start? 2nd click and i have headlights, high beams, and signals, reverse lights. __________________ 71 jimmy bone stock 350 sm465 33x12.5 rallies 79 caprice landau full load crate350 th350 lowered 20"wires 00 f150 reg cab sb 4x4 5.4L

07-01-2011, 12:22 PM	#2
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: light fuse blows, where do i start? a good place to start wood b by reading the board rules about double postings __________________ 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

07-01-2011, 06:50 PM	#3
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: light fuse blows, where do i start? look at the parking lights and the wires. If the harness has been hacked for a trailer plug, I'd start there.

07-01-2011, 10:28 PM	#4
Lee H Registered User Join Date: Jun 2010 Location: Upland Ca Posts: 4,148	Re: light fuse blows, where do i start? Check the grounds. Posted via Mobile Device __________________ 1972 C10 SWB, Air, PS, PB, 350/350THM. Second owner. 1965 Corvette roadster, 44K miles, 327/365 SHP, 4 speed, side exhaust, knockoffs, teak, second owner (bought in 1970), Have ALL numbers matching components. My frame off restoration thread: http://67-72chevytrucks.com/vboard/s...d.php?t=556703

07-01-2011, 10:59 PM	#5
BMERDOC Registered User Join Date: Jun 2011 Location: Richmond,Va Posts: 2,934	Re: light fuse blows, where do i start? Have you done any work recently? Which 20A fuse blew? There are several easily acceible pics of the fuse box to help. I'm still new to the details of these trucks but I'm growing stronger every day. Give us the details and some one here can help. Quick diagnosis for someone who doesnt know a lot about electricity is this. Unplug the taillamp harness at the firewall. Its inside the cab and just above the gas pedal. Pull the light switch to section one, fuse blown? No, Your problem is in the tail lamp section. You have just eliminated everything on the fuse as a source. Plug the taillamp harness back in and unplug at the taillamp connector at the back of the bed (on the left when lookin at the back of the cab just behind the bumper). Retest, blown fuse, yes? Check the taillamp harness for a short to ground. If you initially unpluguged the connector underneath the dash and it did pop, do this. Go to the front connector at the firewall (to the right of the M/C) and unscrew it to unplug it. Retest circuit, blown fuse, no. Check the front harness for bare wire. Its not long and will take minutes to check. If you have a buddy and a small collection of spare fuses you can shake the harnesses to check for the short to ground. These are quick directions for someone who can get around a truck. Again, if you supply more info I'm sure myself or another member would help you with a big smile. I love fixin things. __________________ Nick Carter 1967 C10 Short bed Fleetside Project Cheap Thrills! 2WD C10 Modern/Performance Alignments Easiest Alignment Ever!

07-02-2011, 08:29 PM	#8
mustardjimmy71 toys'r'us Join Date: Nov 2010 Location: Penticton, BC, Canada Posts: 347	Re: light fuse blows, where do i start? Thanks longhorn man and bmerdoc. I unplugged the harness in the rear and there was no blow. I noticed some wires tucked away and they had bare ends. must have been from trailer wireing. Some black tape fixed it up. Still no help from the electrical section __________________ 71 jimmy bone stock 350 sm465 33x12.5 rallies 79 caprice landau full load crate350 th350 lowered 20"wires 00 f150 reg cab sb 4x4 5.4L

07-02-2011, 08:42 PM	#9
BMERDOC Registered User Join Date: Jun 2011 Location: Richmond,Va Posts: 2,934	Re: light fuse blows, where do i start? I'm glad we could help. I haven't been a member of a forum for a long time because of less than desireable members. I found you guys and have been extremely happy. I'll answer any question I think I may be able to help with. ENJOY THAT TRUCK!!!! __________________ Nick Carter 1967 C10 Short bed Fleetside Project Cheap Thrills! 2WD C10 Modern/Performance Alignments Easiest Alignment Ever!



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