pulled to plug off my fuel guage wire down at the tank and it has 3.6V. is this a referencer voltage or should it have 12V
how much power shoulf fuel guage wire carry
Started by
_bunkerjest_
, Aug 01 2010 10:51 AM
3 replies to this topic
#2
ls2lxhatch
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Posted 01 August 2010 - 12:13 PM
The fuel sender has a resistance of 10 ohms (Full) - 73 ohms (Empty).
Voltage to the fuel, oil and temp gauges is supplied by a small silver mechanical regulator on the back of the dash. I have heard that the output voltage of the regulator is 10 volts, someone else may be able to confirm. If the other gauges are working correctly you can rule out the voltage regulator as the problem.
You would need to check the voltage before the gauge as I would expect that the resistance of the gauge would alter the voltage reading at the sender wire.
Some people will earth the sender wire to confirm the gauge is working, this however can damage the gauge. You can safely test the gauge by earthing it to a 10 ohm resistor from Dicksmith/Jaycar which should read full.
Cleaning the sender contacts on the back of the dash and the earth contact often fixes problems.
Voltage to the fuel, oil and temp gauges is supplied by a small silver mechanical regulator on the back of the dash. I have heard that the output voltage of the regulator is 10 volts, someone else may be able to confirm. If the other gauges are working correctly you can rule out the voltage regulator as the problem.
You would need to check the voltage before the gauge as I would expect that the resistance of the gauge would alter the voltage reading at the sender wire.
Some people will earth the sender wire to confirm the gauge is working, this however can damage the gauge. You can safely test the gauge by earthing it to a 10 ohm resistor from Dicksmith/Jaycar which should read full.
Cleaning the sender contacts on the back of the dash and the earth contact often fixes problems.
#3
fuzzypumper
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Posted 01 August 2010 - 07:20 PM
The output voltage of the LH LX dash regulator( which is thermal/mechanical) is 5volts, with a duty cycle of 50% and frequency of 1 hertz.
They average at a max 5volts output.
The guages have an internal resistance of about 10ohms.
The senders are 10ohms(full/hot) to 73ohms(empty/cold).
The sender connect in series to gauge to ground.
If you unplug the wire as you have, and try to measure voltage with a multimeter all your gonna see is the regulators
voltage, that varies all over the place, but can look like 3volts to more than 8volts depending on your multimeter settings.
Im not sure what your trying to achieve here?
They average at a max 5volts output.
The guages have an internal resistance of about 10ohms.
The senders are 10ohms(full/hot) to 73ohms(empty/cold).
The sender connect in series to gauge to ground.
If you unplug the wire as you have, and try to measure voltage with a multimeter all your gonna see is the regulators
voltage, that varies all over the place, but can look like 3volts to more than 8volts depending on your multimeter settings.
Im not sure what your trying to achieve here?
Edited by fuzzypumper, 01 August 2010 - 07:21 PM.
#4
_fryzem_
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Posted 01 August 2010 - 07:40 PM
the reason you are seeing a low voltage like that is the fact that the fuel sender wire carries the earth signal to the guage not the positive signal. so the 3.6volts is actually a resistored feed via the guage winding and then the voltage stabiliser on the back of the dash. it is totally irrelevent to what you are testing by the sounds of it. are you trying to check the reliability of your guage if so the only way you can successfully do this is with a vdo guage checker which is a potentiometer. cheers james
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