Reply
 
Thread Tools Display Modes
 
Old 04-16-2009, 01:56 PM   #1
Skoolie
 
newbusser's Avatar
 
Join Date: Mar 2009
Location: Grays Harbor County, Washington
Posts: 173
Year: 90
Coachwork: blue bird
Chassis: International
Engine: Navistar Straight 6 Turbo
Rated Cap: 65
Fuel guage not working right

Can anyone tell me how to test a fuel sending unit?

I pulled them out and one looks new and other is very old. when they were in, neither was working right, or at least the gauge wasn't reading correctly. I drained both tanks, and when I selected the drivers side tank it said it was empty, select passenger side it says it's full. I then put ten gallons in each side and tried again....no change. Any suggestions?
__________________
“Twenty years from now you will be more disappointed by the
things that you didn't do than by the ones you did do. So throw off
the bowlines. Sail away from the safe harbor. Catch the trade winds
in your sails. Explore. Dream. Discover." Mark Twain
newbusser is offline   Reply With Quote
Old 04-16-2009, 04:15 PM   #2
Bus Nut
 
Join Date: Dec 2006
Location: downriver, detroit mi
Posts: 794
Re: Fuel guage not working right

remove the guages, are the floats empty or full of fuel? if they float hook them up to a ohm meter and slowly move the float assembly thru the range, they should read close to each other in the empty and full positions, if they both test good, adjust the length of the float arms so that the float swings from the bottom of the tank to the top of the tank.
paul iossi is offline   Reply With Quote
Old 04-16-2009, 04:44 PM   #3
Skoolie
 
Join Date: Feb 2005
Location: Winnemucca, NV/Reno NV
Posts: 176
Year: 1980
Coachwork: Gillig 1980, 2003 Thomas E-350 shorty
Chassis: 636/E350
Engine: Cat 3208 NA/7.3
Rated Cap: 78
Re: Fuel guage not working right

And make sure that there are no baffles or other obstructions restricting their movement, both now and when (if) you put them back in.
__________________
If it isn't grown, it has to be mined
http://weathersticker.wunderground.c...Winnemucca.gif
elkoskoolie is offline   Reply With Quote
Old 04-16-2009, 09:27 PM   #4
Bus Geek
 
the_experience03's Avatar
 
Join Date: Feb 2006
Location: Saint James, MN
Posts: 2,669
Send a message via MSN to the_experience03 Send a message via Yahoo to the_experience03
Re: Fuel guage not working right

Disconnect the wiring from the sender. The gauge should read either full or empty. Then ground the connector with a jumper wire. The gauge should move to the opposite end of the spectrum. If it doesn't you have wiring or gauge issues, not sender issues.
__________________
http://farm4.static.flickr.com/3024/...09f20d39_m.jpg
Skooling it...one state at a time...
the_experience03 is offline   Reply With Quote
Old 04-16-2009, 10:52 PM   #5
Bus Nut
 
Join Date: Dec 2006
Location: downriver, detroit mi
Posts: 794
Re: Fuel guage not working right

also chech the tank switch it should measure no resistance, just continuity from guage terminal to one sener terminal or the other.
paul iossi is offline   Reply With Quote
Old 04-17-2009, 01:41 AM   #6
Skoolie
 
newbusser's Avatar
 
Join Date: Mar 2009
Location: Grays Harbor County, Washington
Posts: 173
Year: 90
Coachwork: blue bird
Chassis: International
Engine: Navistar Straight 6 Turbo
Rated Cap: 65
Re: Fuel guage not working right

checked each sending unit on bench.( your suggestion was great Vanguy, I just didn't see it till I had them out
One showed change in ohmmeter, other didn't so I took them both to the truck parts house and ordered another one just like the one that works. They were two totally different styles, now will be the same. I am going to clean the connecting wires completely before I install them and see what happens.
__________________
“Twenty years from now you will be more disappointed by the
things that you didn't do than by the ones you did do. So throw off
the bowlines. Sail away from the safe harbor. Catch the trade winds
in your sails. Explore. Dream. Discover." Mark Twain
newbusser is offline   Reply With Quote
Old 04-18-2009, 10:35 PM   #7
Bus Geek
 
lapeer20m's Avatar
 
Join Date: Nov 2003
Location: near flint michigan
Posts: 2,653
Re: Fuel guage not working right

and make sure the resistance of the sending units is matched to the guage.
__________________
Quis custodiet ipsos custodes (who will watch the watchmen?)
lapeer20m is offline   Reply With Quote
Old 04-18-2009, 10:42 PM   #8
Skoolie
 
newbusser's Avatar
 
Join Date: Mar 2009
Location: Grays Harbor County, Washington
Posts: 173
Year: 90
Coachwork: blue bird
Chassis: International
Engine: Navistar Straight 6 Turbo
Rated Cap: 65
Re: Fuel guage not working right

Still fighting it. I am leaning toward bad grounds, but now when I put new sending unit in, both tanks read full, I put switch to center spot and guage says empty. Am going to clean all connections and try some of the troubleshooting techs tomorrow when I have my son available to tell me what the gauge is doing.

Also, I know the tanks are not full because I ran it dry...... there are a number of four letter words I want to use, but decorum forbids it. Got it running again, but took most of the day.
__________________
“Twenty years from now you will be more disappointed by the
things that you didn't do than by the ones you did do. So throw off
the bowlines. Sail away from the safe harbor. Catch the trade winds
in your sails. Explore. Dream. Discover." Mark Twain
newbusser is offline   Reply With Quote
Old 04-19-2009, 11:55 AM   #9
Bus Geek
 
lapeer20m's Avatar
 
Join Date: Nov 2003
Location: near flint michigan
Posts: 2,653
Re: Fuel guage not working right

you might want to try getting a new guage if the grounds check out. A sending unit and a guage usually come as a matched set. a guage is designed for a certain amount of resistance, and the sending unit is also designed to provide the proper amount of resistance for that particular guage. Having a guage that does not match a sending unit would make things not work properly.
__________________
Quis custodiet ipsos custodes (who will watch the watchmen?)
lapeer20m is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Gas and temp guage malfunction saljal Mechanical and Drivetrains 3 11-20-2013 10:33 AM
When not working on the Skoolie... browncrown Everything Else | General Skoolie Discussions 4 01-21-2013 08:06 PM
STILL working on my bus! KC10Chief Conversion General Discussions 1 08-23-2008 01:46 AM
Sheet metal guage for windows Billsman Conversion General Discussions 12 05-13-2008 05:39 PM
Propane Tank Sending Unit / Fuel Guage Workings Gyva Alternative Fuels | Electric, Propane, Wood Gasification, etc. 3 02-28-2007 11:06 PM

» Virginia Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 08:31 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.