Blowing fuse at "Brakes/Lamps" slot!? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Electrical
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 03-23-2013, 01:04 PM
64Joker's Avatar
64Joker
 
Last photo:
Join Date: Mar 2005
Location: Nor Cal.
Posts: 262
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Blowing fuse at "Brakes/Lamps" slot!?

I'm trouble shooting a problem with blowing a 15 amp fuse on the "brake/lamps" fuse-box slot (with ignition off).
Disconnected the entire main rear wiring harness (tail lights, dome lights, courtesy lights, trunk light), but still blowing fuses.
I'm not experienced in reading wiring circuit diagrams, so I have scanned the entire electrical system and attached 5 files.
I'm interested in any other electrical components that should be tested, and additional suggestions would be appreciated.
I'm working with a 10 amp "circuit breaker" tester at the fuse-box as to not blow any more fuses.

Additional Notes: There are no other electrical issues, engine starts fine and headlights and blinkers work front & back!

Application:

Make: Chevrolet
Model: Impala Ss
Year: 1964
Tran: 350 Auto
Engine: 327 cui
Electrical: HEI
Alternator: 12SI 100 amp
Attached Thumbnails
Click image for larger version

Name:	back-end.jpg
Views:	90
Size:	944.5 KB
ID:	72523   Click image for larger version

Name:	front-end.jpg
Views:	72
Size:	1.61 MB
ID:	72524   Click image for larger version

Name:	fusebox.jpg
Views:	82
Size:	1.49 MB
ID:	72525   Click image for larger version

Name:	under-dash.jpg
Views:	77
Size:	1.71 MB
ID:	72526   Click image for larger version

Name:	Stock Fuse Box.jpg
Views:	457
Size:	306.4 KB
ID:	72527  


    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-23-2013, 01:56 PM
T-bucket23's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Engine basic condition - how to check Last photo:
Join Date: Aug 2005
Location: Massachusetts
Age: 57
Posts: 5,247
Wiki Edits: 26

Thanks: 7
Thanked 121 Times in 106 Posts
Quote:
Originally Posted by 64Joker View Post
I'm trouble shooting a problem with blowing a 15 amp fuse on the "brake/lamps" fuse-box slot (with ignition off).
Disconnected the entire main rear wiring harness (tail lights, dome lights, courtesy lights, trunk light), but still blowing fuses.
I'm not experienced in reading wiring circuit diagrams, so I have scanned the entire electrical system and attached 5 files.
I'm interested in any other electrical components that should be tested, and additional suggestions would be appreciated.
I'm working with a 10 amp "circuit breaker" tester at the fuse-box as to not blow any more fuses.

Additional Notes: There are no other electrical issues, engine starts fine and headlights and blinkers work front & back!

Application:

Make: Chevrolet
Model: Impala Ss
Year: 1964
Tran: 350 Auto
Engine: 327 cui
Electrical: HEI
Alternator: 12SI 100 amp
Most likely a dead short due to a pinched wire. I would start by disconnecting the battery. Take an ohm meter from the load side of the fuse (THE SIDE THAT IS DEAD WHEN IT BLOWS) to ground. This should show a dead short from what you are saying. a meter with a beeper for the continuity test will make this easier.
Follow the wires from the load side of the fuse and you should find the short. Usually the feed goes right to the break light switch so I would take a hard look at that and also unplug the steering wheel harness as the directionals are probably on that circuit. As you unplug things the short will go away, so you will have isolated the different parts of the system. Common issues are the wires that run in the lower rocker channels, shorts in the steering column.
Does the fuse only blow when you step on the break.
The problem with a car that old is many hands have probably been in there and some may have not been very skilled.
__________________
Artificial Intelligence is no match for Natural Stupidity



Chet
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-23-2013, 02:04 PM
64Joker's Avatar
64Joker
 
Last photo:
Join Date: Mar 2005
Location: Nor Cal.
Posts: 262
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Follow-up

Quote:
Originally Posted by T-bucket23 View Post
Does the fuse only blow when you step on the break.
The fuse blows as soon as I put a new fuse into the slot, no ignition "on" or anything! I will proceed as you suggested. Thanks!
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-23-2013, 02:13 PM
EOD Guy's Avatar
Registered User
 
Last photo:
Join Date: Aug 2010
Location: Alabama
Posts: 2,065
Wiki Edits: 0

Thanks: 1
Thanked 135 Times in 126 Posts
I'd start by unbolting the fuse box from the firewall and look for a broken/frayed wire or evidence of a short, from there I'd trace the loom and look behind the driver's kick panel, from there I'd look underr the wire chase protector under the drivers side sill plate (I'm not sure if that's where it's at on a 64 but that's where it's at on my 67).

Sounds as if you have a direct short due to a misplaced screw, or 40 plus years of driving, rubbing a wire thru' etc....
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-23-2013, 02:36 PM
Registered User
 
Join Date: Nov 2004
Location: California
Age: 67
Posts: 830
Wiki Edits: 0

Thanks: 27
Thanked 23 Times in 20 Posts
I think I'd approach this by testing from the load side of the fuse to the power side of the brake switch.

PatM
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 03-23-2013, 07:56 PM
Bryan59EC's Avatar
Car? Truck? Who Cares
 

Last journal entry: First week of December
Last photo:
Join Date: Jun 2006
Location: San Antonio, Texas
Age: 54
Posts: 2,369
Wiki Edits: 0

Thanks: 2
Thanked 27 Times in 22 Posts
Disconnect the intermediate harness and check again.
The intermediate is also subject to abuse, but the only constantly hot wire in there is the dome light----may very well be a black wire in that harness.
(Black and white are also common older GM dome circuits---black is hot--white is return)(turns out 64 is orange/black feed with a white ground)

If the fuse will stay together with the intermediate unhooked---it will be dome light issue---might be as simple as a bad terminal in the dome light.

BTW--that connector is behind the driver side kick panel or just above it.
will be an 8 conductor connector with 7 wires in it.


If not this harness----could be the orange wire from the fusebox to the
brake switch----or an orange wire feeding the headlight switch

(might be orange and black)

There is a splice in the harness coming from that fuse that feeds:
Brake lights---taillight feed---dome light feed---clock

These are the 4 items you need to look at.
Even if you have no clock---there is a feed for it in the harness
Dome lights---remove all the bulbs--or disconnect the harness to the dome/courtesy lamps.

Disconnect the headlight switch connector----eliminate a shorted switch

check for a bare or shorted wire near the brake light switch.

64 must be the year GM started changing some wire colors.
half of the colors on your drawings match my 59--but some are more current and are closer to the current standard.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-24-2013, 09:36 AM
64Joker's Avatar
64Joker
 
Last photo:
Join Date: Mar 2005
Location: Nor Cal.
Posts: 262
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Follow-up Question

Could this problem by any chance be at the "ignition switch"?
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 03-24-2013, 11:40 AM
64Joker's Avatar
64Joker
 
Last photo:
Join Date: Mar 2005
Location: Nor Cal.
Posts: 262
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Bryan, Could this problem by any chance be followed back to the ignition switch??? Thanks, Al

------------------------------------------------------------------------------------------------------------------
Disconnect the intermediate harness and check again.
The intermediate is also subject to abuse, but the only constantly hot wire in there is the dome light----may very well be a black wire in that harness.
(Black and white are also common older GM dome circuits---black is hot--white is return)(turns out 64 is orange/black feed with a white ground)

If the fuse will stay together with the intermediate unhooked---it will be dome light issue---might be as simple as a bad terminal in the dome light.

BTW--that connector is behind the driver side kick panel or just above it.
will be an 8 conductor connector with 7 wires in it.


If not this harness----could be the orange wire from the fusebox to the
brake switch----or an orange wire feeding the headlight switch

(might be orange and black)

There is a splice in the harness coming from that fuse that feeds:
Brake lights---taillight feed---dome light feed---clock

These are the 4 items you need to look at.
Even if you have no clock---there is a feed for it in the harness
Dome lights---remove all the bulbs--or disconnect the harness to the dome/courtesy lamps.

Disconnect the headlight switch connector----eliminate a shorted switch

check for a bare or shorted wire near the brake light switch.

64 must be the year GM started changing some wire colors.
half of the colors on your drawings match my 59--but some are more current and are closer to the current standard.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 03-24-2013, 05:48 PM
64Joker's Avatar
64Joker
 
Last photo:
Join Date: Mar 2005
Location: Nor Cal.
Posts: 262
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Update

I think I've found the problem, after further analysis, it appears the issue is leading back to one of the "console" lights!
I will have to trace it back tomorrow and report back!
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 03-24-2013, 06:57 PM
Bryan59EC's Avatar
Car? Truck? Who Cares
 

Last journal entry: First week of December
Last photo:
Join Date: Jun 2006
Location: San Antonio, Texas
Age: 54
Posts: 2,369
Wiki Edits: 0

Thanks: 2
Thanked 27 Times in 22 Posts
My personal belief is that you will find something with the dome/courtesy circuit.

Don't know where the connector is for a 64 Chevy console, but 66 Chevelle had
a pigtail in the main harness (only on console equipped cars), a short harness about 15" long that connected to the console harness.

Probably 3 wires in that console----
orange wire---feeding courtesy lamps lamps and branched out to a console clock if equipped.

grey wire----shift indicator lamp--clock lamp

white wire-----dome/courtesy ground

no common black wire for ground---common will probably be a screw or clip attached to a console bracket.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 03-25-2013, 05:46 PM
64Joker's Avatar
64Joker
 
Last photo:
Join Date: Mar 2005
Location: Nor Cal.
Posts: 262
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Update - Fixed!!!

Traced the issue back to a 2 wire connector off the main console pigtail.
After disconnecting the plastic connector (black/org & black/white wires), the 15amp brake/lamp fuse stopped blowing! Whoo Hoo! All tail/brake lights and courtesy lights now working.
Now to trace the actual issue at the console level, should be a simple fix!

Thanks for all your help fellows!
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 03-25-2013, 07:31 PM
EOD Guy's Avatar
Registered User
 
Last photo:
Join Date: Aug 2010
Location: Alabama
Posts: 2,065
Wiki Edits: 0

Thanks: 1
Thanked 135 Times in 126 Posts
Good to hear you got it narrowed down
Reply With Quote Quick reply to this message

Recent Electrical posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Kill Swith "Keep-Alive" bypass fuse rating kbuhagiar Electrical 4 07-17-2011 10:54 AM
No power from "BAT" terminal on fuse block for3300 Electrical 2 07-16-2010 06:17 PM
Chevy 355 Blowing Oil "help" dran04u Engine 4 10-14-2004 11:07 PM
Hey croz look """"IMPORTS SUCK""" 78 monte Hotrodders' Lounge 14 08-30-2002 01:13 PM


All times are GMT -6. The time now is 11:08 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.