| Fuel Tank Sender [message #63676] |
Tue, 10 November 2009 10:16  |
 |
JShot
Messages: 485
Registered: October 2006
Location: NW Ohio
Karma: 0
|
Senior Member |
|
|
Our dash fuel gauge has always been pretty good at telling us what's in the tanks. But on a recent trip, when switching from the main to the aux tank, the main showed a little more than a half tank full, but the aux pinned the needle on empty. Switching a few times didn't change the readings.
I left the switch in the aux position for a few miles, and the engine didn't die. Does this mean the aux sending unit has finally gone south? Or could there just be a wiring problem???
Thanks,
John
John Shotwell
Ridgeville Corners, OH
78 Royale Center Kitchen
|
|
|
|
|
|
| Re: Fuel Tank Sender [message #63695 is a reply to message #63676] |
Tue, 10 November 2009 11:40  |
 |
mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
|
Senior Member |
|
|
| JShot wrote on Tue, 10 November 2009 08:16 |
...when switching from the main to the aux tank, the main showed a little more than a half tank full, but the aux pinned the needle on empty. ..... Does this mean the aux sending unit has finally gone south? Or could there just be a wiring problem???
|
An empty reading on the gauge says that the gauge is seeing ground. (If it was an open circuit, it would read max full.)
As the main tank is reading ok, the problem is between the selector valve and the tank sending unit. So... yes it could be your sender.... could be something else. (Wire and valve.)
You can only check the valve and a short bit of wire without dropping your tank. If it is not the valve, I would wait until you drop the tanks for some other reason before worrying about it. -- As the rear (main) sensor reads the level in both tanks until they get down to 1/4 tank, many only use one sender and do not have issues.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
|
|
|
|
|
|
| Re: Fuel Tank Sender [message #63727 is a reply to message #63723] |
Tue, 10 November 2009 16:57 |
 |
WD0AFQ
Messages: 7111
Registered: November 2004
Location: Dexter, Mo.
Karma: 207
|
Senior Member |
|
|
| JShot wrote on Tue, 10 November 2009 16:38 |
Thanks for your analysis. I was hoping it might be a wiring issue. The tanks definitely need to be dropped and re-plumbed, and if they're like the brake system, probably have never been done (it's original). But, so far, she's gotten us over 10,000 miles since we got her in December of '07, and that makes us happy campers!
John
|
John, that is a good testimony to the reliability of these old coaches. Why don't we see if we can drop your tanks next year, at the Miller's, if you don't do it before?
or
Maybe you might put about 4 of us up for a week, with our families, and we will come over and tell you how to do it in that new barn. 
Dan
3 In Stainless Exhaust Headers
One Ton All Discs/Reaction Arm
355 FD/Quad Bag/Alum Radiator Manny Tran/New eng.
Holley EFI/10 Tire Air Monitoring System
Solarized Coach/Upgraded Windows
Satelite TV/On Demand Hot Water/3Way Refer
|
|
|
|
| Re: [GMCnet] Fuel Tank Sender [message #63730 is a reply to message #63723] |
Tue, 10 November 2009 17:14 |
 |
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
|
John,
When you do drop the tanks to re-plumb them you might want to consider:
1) Coating the inside of the tank with a fuel tank liner (won't have
problems with rust again.)
2) Removing the internal sock and fitting external filters (if crud does get
into the tank you can easily get rid of it.)
3) Bending the pickup lines to the bottom of the tank (you will get a bit
more fuel out of the tanks.)
4) Using solid lines across the top of the tank to the side (you won't have
to worry about crushing the lines or having them deteriorate.)
5) Seperating the vent lines (the tanks will fill easier.)
Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of John Shotwell
Sent: Wednesday, 11 November 2009 9:38 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] Fuel Tank Sender
Thanks for your analysis. I was hoping it might be a wiring issue. The tanks
definitely need to be dropped and re-plumbed, and if they're like the brake
system, probably have never been done (it's original). But, so far, she's
gotten us over 10,000 miles since we got her in December of '07, and that
makes us happy campers!
John
--
John Shotwell
Archbold, OH
78 Royale Center Kitchen
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
