FGF Advertisement Sponsor

Forums

Previous Thread
Next Thread
Print Thread
Rate Thread
#59175 10/08/06 03:41 PM
Joined: Aug 2005
Posts: 28
Member
Member
Joined: Aug 2005
Posts: 28
my gas gauge is always reading FULL (69 bird) I disonnected the wire in the trunk and with the key on grounded it and watched the gauge. The gauge went to E. Is my problem the gauge or sending unit?

Google AdSence Sponsor for FGF Forums
Joined: Jan 2005
Posts: 1,222
6
Member
Member
6 Offline
Joined: Jan 2005
Posts: 1,222
Your dash gauge is okay because it goes to E when you ground the sender circuit. When the sender circuit is open, the gauge will actually read beyond full.

So you have an open circuit in the sender circuit or the sender is bad. An open circuit can be caused by loss of the ground connection or a problem in the wiring or associated connectors. To troubleshoot this, try unplugging the wire right at the sender and jumper it to ground. If the gauge goes to "E", then the wiring all the way to the sender is good.

There is a ground return wire from the sender. This wire can break through the years. Inspect this short black wire, which is around 9" long and replace it if it's broken from the lug or the connection is bad.

If you find a good solid circuit to the sender and the ground is solid also, that leaves the sender itself. The sender is wire wound resistor with a slider connected to the float. This wire is fragile and eventually it wears through. Sometines connections to this nichrome wire corrode, causing the sender to fail open. You can check the sender with an ohm meter as a last step before spending money on a replacment. It should not read open circuit from its hot pin to ground, even with the tank empty.


Joined: Aug 2005
Posts: 28
Member
Member
Joined: Aug 2005
Posts: 28
Thanks, I also hooked up a potentiometer to the unplugged cable in the trunk leading to the gauge and was able to see the gauge move as I turned the pot. Must be a bad sending unit from that test and what you've said in your post.


Link Copied to Clipboard
Forum Statistics
Forums57
Topics35,545
Posts298,893
Members8,865
Most Online19,810
Feb 1st, 2026
Who's Online Now
0 members (), 87 guests, and 20 robots.
Key: Admin, Global Mod, Mod
Newest Members
bird400, JFF, BjarteTA, Fireball1955, zinger223
8,865 Registered Users
Top Posters(30 Days)
dillin 1
Rus 1
Top Posters
Bjorn Sefeldt 20,054
Fbody69 14,265
Yellowbird 11,905
68tpls400 10,338
salmon38 7,719
Firebob 7,495
Banshee 7,408
Gus68 6,758
Today's Birthdays
There are no members with birthdays on this day.
Photo Gallery
My latest 67 vert project rust bucket
My latest 67 vert project rust bucket
by Firebob, December 22
My weekend warrior
My weekend warrior
by Two67Firebirds, August 1
Cool dragster
Cool dragster
by Gus68, March 26
67 at Warbird show
67 at Warbird show
by Revvingup, December 31
With the old hood on.
With the old hood on.
by Firebob, July 29
Forum Search
NOTE: Search FGF Forums functions differently than the Search found at the top
Powered by UBB.threads™ PHP Forum Software 8.0.1