fuel gauge sender, Bench testing |
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fuel gauge sender, Bench testing |
80cap |
Dec 5 2016, 01:46 PM
Post
#1
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Member Group: Members Posts: 317 Joined: 6-February 15 From: ohio Member No.: 18,405 Region Association: None |
Before I install my fuel tank is there a way to bench test the fuel level sending unit?
Thanks Brian |
Retroracer |
Apr 13 2021, 02:25 PM
Post
#2
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Senior Member Group: Members Posts: 609 Joined: 7-July 13 From: Bend OR Member No.: 16,100 Region Association: Pacific Northwest |
So that would point to either wiring or gauge being incorrect. 0 - 70 ohms is about right for the sender. Couple of things to check:
1) with the sender disconnected, take off the sender wire at the gauge. Measure the resistance to GND on the wiring. There should be none measurable (high impedance), BUT if the wiring has a resistive short to GND, then that would throw the "empty" reading off. 2) make sure the +12V feed to the gauge is fused, switched 12V - not via anything random or resistive (like a backlight bulb). It is always surprising how creative PO's can get with wiring "fixes".... 3) make sure the combo gauge has a GND connection to chassis (so it isn't trying to GND itself through the sender) 4) if the sender is disconnected from the gauge, with power on, does it read "empty"? If you then short the sender terminal to GND does it read "full"? If not your gauge is broken... Hope this helps, - Tony PS. The obvious question: is your petrol tank half full? ;-) |
neilbardsley |
Apr 14 2021, 12:50 AM
Post
#3
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Newbie Group: Members Posts: 25 Joined: 11-October 20 From: England Member No.: 24,754 Region Association: Europe |
So that would point to either wiring or gauge being incorrect. 0 - 70 ohms is about right for the sender. Couple of things to check: 1) with the sender disconnected, take off the sender wire at the gauge. Measure the resistance to GND on the wiring. There should be none measurable (high impedance), BUT if the wiring has a resistive short to GND, then that would throw the "empty" reading off. 2) make sure the +12V feed to the gauge is fused, switched 12V - not via anything random or resistive (like a backlight bulb). It is always surprising how creative PO's can get with wiring "fixes".... 3) make sure the combo gauge has a GND connection to chassis (so it isn't trying to GND itself through the sender) 4) if the sender is disconnected from the gauge, with power on, does it read "empty"? If you then short the sender terminal to GND does it read "full"? If not your gauge is broken... Hope this helps, - Tony PS. The obvious question: is your petrol tank half full? ;-) Thank you. I will try those. The tank isn't half full (IMG:style_emoticons/default/smile.gif) |
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