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| | | | Joined: Jun 2011 Posts: 59 Wrench Fetcher | | Wrench Fetcher Joined: Jun 2011 Posts: 59 | 54 gmc converted to 12v. reading 24v at battery. back of the fuel gauge reads 24.8 and 11.4 at sender. what could be going on? | | | | | Joined: Feb 2002 Posts: 12,029 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Feb 2002 Posts: 12,029 | you're reading the wrong scale on the meter? you've got 2 batteries? with a 12V battery it'd be pretty hard to get 24V unless you've got an alternator on steroids
Bill | | | | | Joined: Jun 2011 Posts: 59 Wrench Fetcher | | Wrench Fetcher Joined: Jun 2011 Posts: 59 | yep wrong scale. well now the back of the fuel gauge reads 11.8 and the top of the fuel tank sender reads 1.8. the gauge is brand new as is the fuel sender. grounding the sender the gauge sweeps. grounds are on bare metal. stumped. any ideas?? | | | | | Joined: Feb 2002 Posts: 12,029 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Feb 2002 Posts: 12,029 | voltage at the sender is irrelevant, the sender supplies the ground for the gauge and you're reading thru it's resistance .... if "odd" readings are the only problem, quit reading  does the gauge work properly? [grounding it should make it move] Bill | | | | | Joined: Jun 2011 Posts: 59 Wrench Fetcher | | Wrench Fetcher Joined: Jun 2011 Posts: 59 | the gauge moves when the sender is disconnected. yes. | | | | | Joined: Jun 2011 Posts: 59 Wrench Fetcher | | Wrench Fetcher Joined: Jun 2011 Posts: 59 | i hooked up a wire directly from the battery to the gauge and clean grounds on both sender and gauge. it is a 12v vdo gauge. the sender is brand new. | | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | With the sender grounded you should see an empty reading. With the sender disconnected you should see a full reading. Moving the sender through it's range, I would expect to see it go from 0 to 30 ohms, or close to it. | | | | | Joined: May 2001 Posts: 7,438 Extreme Gabster | | Extreme Gabster Joined: May 2001 Posts: 7,438 | i hooked up a wire directly from the battery to the gauge and clean grounds on both sender and gauge. it is a 12v vdo gauge. the sender is brand new. Are the sender and gauge matched? A stock gauge uses a 0-30 ohm sender. The VDO gauge may or may not. | | | | | Joined: Jun 2011 Posts: 59 Wrench Fetcher | | Wrench Fetcher Joined: Jun 2011 Posts: 59 | yep got off the phone with vdo. they are sending me the matched fuel sender. will get it next week and see what happens. | | | | | Joined: Jan 2008 Posts: 159 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 159 | voltage at the sender is irrelevant, the sender supplies the ground for the gauge and you're reading thru it's resistance .... if "odd" readings are the only problem, quit reading does the gauge work properly? [grounding it should make it move] Bill Red that is the best explanation I have ever heard for the fuel gauge/sending unit
1938 Gmc 1/2 ton
| | | | | Joined: Jun 2011 Posts: 59 Wrench Fetcher | | Wrench Fetcher Joined: Jun 2011 Posts: 59 | So got the part from VDO today installed it and popped right up on the gauge. right sender right reading. thanks | | |
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