Help!!! Fuel Gauge Problems - 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 08-09-2010, 05:34 PM
69Bowtie's Avatar
Registered User
 
Join Date: Aug 2010
Location: NC
Posts: 36
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Help!!! Fuel Gauge Problems

I've got a 69 Camaro and the fuel gauge needle registers about an inch past full. I've disconnected the wiring harness that supplies the sending unit in the trunk but it made no difference. Reading ohms from the tan wire in the trunk it reads about 35 ohms. I've tried a new fuel gauge but it does the same thing. The plug at the gauge reads 11.4 V on the red wire that supplies the gauge & 8.47 V on the tan wire in the trunk that supplies the sending unit when the switch is on. Any help would be greatly appreciated.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-09-2010, 06:04 PM
LATECH's Avatar
Hotrodders.com Moderator
 

Last journal entry: Motor - vator
Last photo:
Join Date: Jul 2010
Location: Northeast Pennsylvania
Posts: 5,166
Wiki Edits: 0

Thanks: 199
Thanked 249 Times in 231 Posts
the fuel gauge has a drop resistor in it (on the back of the gauge itself) and it sounds like it is ok as you have the 8 ish volts back to the unit.the gauge will read over the top when there is an open ciruit on the gauge to sender circuit. You have verified the wiring to the tank, so that leaves the tank sender unit or the ground wire. Easier to at least first check the ground wire but also you can ohm the tank unit circuit without removing it ( as a presumptive to pulling the tank unit which is next)the unit will read somewhere between 10 to 95 ( roughly) if it is working and depending on how much fuel is in it. If it is like my 64 poncho the sending unit( It is ) has a ground lead that goes to the frame that is attached to the metal frame of the unit itself as the tank unit flange ring is not a reliable connection and tanks are usually mounted with rubber straps that insulates them ( keeps the straps from rubbing a hole in the tank) Hope this helps
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-09-2010, 06:22 PM
69Bowtie's Avatar
Registered User
 
Join Date: Aug 2010
Location: NC
Posts: 36
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Reading between the tan wire of the sending unit in the trunk & ground I get about 12 M ohms. I have checked the ground wire at the frame and it looks good. Does this sound as if the sending unit is bad to you latech?
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-09-2010, 07:01 PM
LATECH's Avatar
Hotrodders.com Moderator
 

Last journal entry: Motor - vator
Last photo:
Join Date: Jul 2010
Location: Northeast Pennsylvania
Posts: 5,166
Wiki Edits: 0

Thanks: 199
Thanked 249 Times in 231 Posts
Yea, 12 megohm is way too high. about a million times too high sounds like the tank unit will have to come out.you may find corrosion at the crimp connections at the sending unit lead or ground lead to be the issue.bench test it to be sure you may be able to make a good repair without replacing much of anything. try to keep the gm oem
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-09-2010, 07:07 PM
LATECH's Avatar
Hotrodders.com Moderator
 

Last journal entry: Motor - vator
Last photo:
Join Date: Jul 2010
Location: Northeast Pennsylvania
Posts: 5,166
Wiki Edits: 0

Thanks: 199
Thanked 249 Times in 231 Posts
Ive seen a lot that of units that the resistance wire needed cleaned and the contact tip that is in bad shape.You can remove the side cover from the sender. Study it and keep the ohmeter turned on ( checking at each contact spot). like I said you can probably fix it . I repaired the one in my poncho. all it needed was the resistance wire cleaned ( carefully) i used a little 400 wet sand very lightly on the contact area and it worked good when i was through.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 08-09-2010, 08:15 PM
69Bowtie's Avatar
Registered User
 
Join Date: Aug 2010
Location: NC
Posts: 36
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
thanks a buch, you've been a great help. Send me a couple pictures of your poncho if you get time.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-10-2010, 03:41 PM
LATECH's Avatar
Hotrodders.com Moderator
 

Last journal entry: Motor - vator
Last photo:
Join Date: Jul 2010
Location: Northeast Pennsylvania
Posts: 5,166
Wiki Edits: 0

Thanks: 199
Thanked 249 Times in 231 Posts
OK I will look around for a pic of my project.I should put it in my avatar actually . Thank you kindly for asking
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
fuel gauge problems Bracewell Engine 1 10-26-2009 05:19 PM
fuel gauge problems grapro Electrical 5 03-16-2009 01:13 PM
Guages are dead gtipton Electrical 4 05-09-2007 09:14 PM
Fuel level gauge question mattson70 Electrical 1 02-23-2007 05:50 PM
Fuel gauge problems 1969NovaSS Electrical 5 05-04-2006 11:42 PM


All times are GMT -6. The time now is 09:23 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.