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#91192 04/25/2004 4:27 PM | Joined: Apr 2004 Posts: 219 Shop Shark | | Shop Shark Joined: Apr 2004 Posts: 219 | Ok Guys, My fuel gage only works with the park/headlamps on. I've checked the circuit on the sender side, good ground & continuity up to the gauge. I've got battery voltage at the gauge.
Pink wire is batt., tan wire is the sender. With the test results I have gathered, the gauge should work. But, It only reads accurately when the lights are switched on. Now, I thought I was fairly knowledgeable when it came to electrical, I can fix 30k $ Caddy's all weak long. But, this one has got me baffled. Anyone have this problem before?? Thanks in advance.
Jim Sgrig | | |
#91193 04/25/2004 4:35 PM | Joined: Apr 2004 Posts: 219 Shop Shark | | Shop Shark Joined: Apr 2004 Posts: 219 | Sorry, it's a '66 Panel. Also, I can't find sender resistance values in the shop manual. Does anyone know what the resistance range is?
Thanks,
JS | | |
#91194 04/25/2004 5:24 PM | Joined: Feb 2004 Posts: 29,760 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,760 | Check the resistance between the tank and the frame. I'll bet you've got a bad ground in there somewhere. Try running a ground wire from the sending unit where it bolts into the tank, to a known good chassis ground. Also check the instrument panel ground to the dash. Anytime turning on another circuit alters the performance of something, there's a grounding problem somewhere.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
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#91195 04/25/2004 5:25 PM | Joined: Sep 2003 Posts: 2,384 Shop Shark | | Shop Shark Joined: Sep 2003 Posts: 2,384 | Try adding an extra ground wire from one of the screws on back of inst panel to a good ground under the dash, just use a 12-18 ga wire & coupla terminals. Brian | | |
#91196 04/25/2004 5:53 PM | Joined: Apr 2004 Posts: 219 Shop Shark | | Shop Shark Joined: Apr 2004 Posts: 219 | My suspicions are a bad ground. I've already cleaned the ground back at the tank to the sender.I ran a redundant ground to the cluster, no change. According to the schematic, the gauge & lights don't share any common grounds/ciruits.
Unless, the gauge is grounded to the cluster interally where it mounts?? I think I'll pull the cluster & check/clean the mounting points.
Thanks for the input guys.
JS | | |
#91197 04/25/2004 6:08 PM | Joined: Feb 2004 Posts: 29,760 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,760 | The gauge is a "balancing-coil" type, with one coil getting full voltage, and grounding to the dash. The other coil grounds through the sending unit. Both coils have to function properly for the gauge to read right. Check the gauge-to-dash panel circuit for a high-resistance connection.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
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#91198 04/25/2004 6:28 PM | Joined: Apr 2004 Posts: 219 Shop Shark | | Shop Shark Joined: Apr 2004 Posts: 219 | Check the gauge-to-dash panel circuit for a high-resistance connection.
Thanks Hotrod, that's where I was headed next. The one coil probably isn't grounded to cluster.
It got to be picking up the groung through the dash lamps when the lights are switched on.
Thanks again for your input.
JS | | |
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