protecting a gauge - 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 04-05-2011, 06:03 PM
GMR GMR is offline
Registered User
 
Last photo:
Join Date: Sep 2006
Location: florida
Posts: 290
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
protecting a gauge

I want to protect whats called the "battery gauge" on a '64 vette. Here's the layout.

Wire from Alt Bat terminal goes to horn relay. The horn relay terminal has 3 wires all spliced together in same connector. BLk/wht goes to "battery gauge", red (red-1 say) goes to big terminal on starter solenoid, another red (red-2 say) goes to a junction of red wires which feed the ign sw bat term, fuse panel, several accesories. Back at the starter solenoid, the red-1 is spliced into same connector as a black wire. This black wire goes to other side of "battery gauge".

So I want to protect this "battery gauge". Not sure where to install fusible links and/or any inline fuses, and what gauge of fuse if required. I know the fusible links should be 2 wire gauges smaller (12ga requires 16ga fl).

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 04-05-2011, 11:37 PM
Registered User
 
Last photo:
Join Date: Jan 2006
Location: Nanaimo, B.C., Canada
Posts: 671
Wiki Edits: 0

Thanks: 3
Thanked 18 Times in 18 Posts
If you want to fuse it it'll have to be a big fuse. At least the max amps of the alternator. All the charge from the alternator to the battery goes through the guage. I would think you'd want the fuse on the alternator side of the ammeter. If a wire shorts there you would have full power from the battery going through the gauge to ground, if it shorts on the other side you'd have the alternator power going through it, which it's rated for.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 04-06-2011, 02:31 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
I believe your "Battery Gauge" is basically a galvanometer. As such it isn't 'actively' connected to the vehicle battery current, so really shouldn't need any protection per se.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 04-06-2011, 04:31 AM
Registered User
 
Join Date: Aug 2006
Location: Alexandria, VA
Posts: 1,762
Wiki Edits: 0

Thanks: 4
Thanked 66 Times in 64 Posts
I'd have to diagram it out to be sure, but it sounds like you have an ammeter gauge that uses a shunt. If that is the case, it is not a full current ammeter. Its just measuring the voltage difference between two points in the harness and calculating amperage.

My '75 GMC has a gauge wired like this, and it just uses a five amp fuse in each wire that connects to the gauge. They are inline fuses that are in the wire lines under the hood. The actual amperage flow to the gauge when you use a shunt is quite low.

Bruce
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 04-06-2011, 05:23 PM
GMR GMR is offline
Registered User
 
Last photo:
Join Date: Sep 2006
Location: florida
Posts: 290
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks fellas.

Here's a diagram. Could you please give me your recommendations on where to put fusible links/fuses/circuit breakers.

Hope you can read it.

The Red-2, Blk/Wht, and Red-3 share a ring terminal at the horn relay.
The Red-3 and Blk share a ring terminal at the starter solenoid.

I'm guessing I should separate and put fusible links on Red-2 at the starter solenoid and Red-3 at the horn relay. Probably, to be safe, I'll put the inline fuses on the Blk and BLk/Wht wires to the battery gauge as mentioned. Looks to me the cig lighter is unprotected or will a fusible link at Red-3 do the job?

Would you ever use a fuse and a fusible link on same circuit?
Attached Thumbnails
Click image for larger version

Name:	IM000969.JPG
Views:	89
Size:	787.3 KB
ID:	54247  

Last edited by GMR; 04-06-2011 at 05:36 PM.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 04-09-2011, 07:55 PM
Registered User
 
Last photo:
Join Date: Sep 2009
Location: GTA
Posts: 41
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Unless I'm missing something ( a bit fuzzy) the way you've drawn it the gauge is shorted by a red wire?. Don't see how that works.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 04-09-2011, 09:01 PM
GMR GMR is offline
Registered User
 
Last photo:
Join Date: Sep 2006
Location: florida
Posts: 290
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Not sure what you mean. The 2 wires to the battery gauge are a BLK from starter solenoid and Blk/Wht from horn relay. I'll try a more clear diagram.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 04-09-2011, 10:08 PM
Registered User
 
Last photo:
Join Date: Sep 2009
Location: GTA
Posts: 41
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Where you have 3 wires going into a "box" if they are attaching to separate distinct terminals on the "box" maybe you can show that.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 04-10-2011, 02:25 PM
vicrod's Avatar
life is a ride
 

Last journal entry: 2014
Last photo:
Join Date: Nov 2005
Location: Telford, PA
Age: 71
Posts: 1,341
Wiki Edits: 0

Thanks: 0
Thanked 59 Times in 55 Posts
The battery meter is an ammeter. It will have a 0 amps centered position and + amps and - amps positions.
An indication in the + side of the ammeter shows if current is flowing from the alternator to the battery.
An indication in the - shows excess current flowing from the battery to the accessories or the alternator is not working.

The ammeter measures voltage drop across a shunt. In this case the shunt is the heavy red wire connecting the battery to the alternator and accessories.
The smaller black and blk/wt wires go to the ammeter. If they are not fused they should be.
Inline fuses (4 amp) should be installed in each of these wires at a point as close as possible where it connects to the heavy red wire.

vicrod
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 04-10-2011, 06:40 PM
Registered User
 
Last photo:
Join Date: Sep 2009
Location: GTA
Posts: 41
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
If its a typical meter movement then the flow would be milliamps? I would postulate 4A may protect the attaching wires but protecting the movement may require something very small, say under 1A?
If its configured differently I'd enjoyed being enlightened.
(not intended as a bad electrical pun)
D
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 04-12-2011, 08:13 AM
GMR GMR is offline
Registered User
 
Last photo:
Join Date: Sep 2006
Location: florida
Posts: 290
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Hope this is a more readable.

I plan to install inline fuses on the battery gauge wires, as suggested, after things are worked out - thanks.

The red and blk wires at the sol share a spade connector. The two reds and the blk/wht share a connector at the horn relay. The horn relay has 2 terminals but they are on the same bus bar.
Attached Thumbnails
Click image for larger version

Name:	IM000970.jpg
Views:	499
Size:	736.4 KB
ID:	54383  
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 04-12-2011, 02:42 PM
vicrod's Avatar
life is a ride
 

Last journal entry: 2014
Last photo:
Join Date: Nov 2005
Location: Telford, PA
Age: 71
Posts: 1,341
Wiki Edits: 0

Thanks: 0
Thanked 59 Times in 55 Posts
I suggested 4 amp fuses only because the GM schematics show them.

vicrod
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 04-12-2011, 02:50 PM
malc's Avatar
Living At The Speed Of Life
 
Last photo:
Join Date: Jun 2003
Location: Espaņa Right Coast
Posts: 3,266
Wiki Edits: 0

Thanks: 91
Thanked 94 Times in 80 Posts
If it is an ammeter, read this.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 04-12-2011, 03:09 PM
vicrod's Avatar
life is a ride
 

Last journal entry: 2014
Last photo:
Join Date: Nov 2005
Location: Telford, PA
Age: 71
Posts: 1,341
Wiki Edits: 0

Thanks: 0
Thanked 59 Times in 55 Posts
The article supports my position that the meter shunt in GM alternator equipped cars is the main accessory wire which is part the main harness and does NOT pass into the passenger compartment and through the ammeter.
Any vehicle that has the shunt as part of the ammeter can be hazardous as mentioned in the article.

vicrod
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 04-13-2011, 08:54 PM
GMR GMR is offline
Registered User
 
Last photo:
Join Date: Sep 2006
Location: florida
Posts: 290
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Good article malc, thanks.
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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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
Hiding & protecting my wiring Irelands child Electrical 3 07-18-2008 06:23 AM
Protecting the starter on a sbc joe350s10 Engine 13 06-04-2006 04:38 PM
protecting underside of old fenders jcarter Body - Exterior 15 07-02-2004 01:41 PM
Protecting yourself Hellzapoppin Hotrodders' Lounge 25 08-01-2003 09:09 AM
Protecting Body Filler bmech211 Body - Exterior 3 06-03-2003 07:39 PM


All times are GMT -6. The time now is 07:12 AM.


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.