Finding polarity
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Joined: Feb 2002
Posts: 698
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Neon Tube?
I'm not sure what you mean by neon tube?
But if you are talking about a 12volt DC voltage source like what feeds the cig lighter, or utility power receptacle, or vanity lights, etc. There are a few ways you can go about it.
The BEST way would be to get your hands on ANY kind of voltmeter. Any old cheapy type would do... it could even be an old Simpson analog meter. If you are trying to determine which wire is positive and which wire is ground (negative)... Take the negative lead of the voltmeter and touch it to chassis ground. Then take the positive lead of the voltmeter and touch each wire SEPARATELY. One wire will read around +12volts and the other lead will read zero volts or very near it. This tells you which wire is sourcing the POSITIVE voltage. THAT WOULD BE YOUR POSITIVE WIRE. The other wire would be negative.
If you can't beg, borrow, or steal a voltmeter... Find something small that runs off of 12volts. Get any automobile inside dome light or vanity bulb. Get a clip lead and attach one end to chassis ground, and one end to any terminal of the light bulb... Then touch each of the two wires (one at a time) to the other terminal of the light bulb. One wire will cause the bulb to light and one will not. The one that lights the bulb will be the HOT wire which will be your positive wire. The other wire will be the ground wire or negative wire. This assumes that the negative wire is at ground potential, or very nearly so. That should be the case with any power wire in the car... but again I don't know what you're talking about with a NEON bulb. NEON BULBS TAKE 90VOLTS TO LIGHT UP???? So either you've got some aftermarket gag with an unknown power supply that may or may not float from ground, or you have simply called it a neon bulb by mistake.
If you are talking about common 12volt power wires running throughout the TL, then my test methods should easily tell you which wire is which. Of course you will have to have power supplied to the wires for the light bulb or voltmeter test to work. So you may have to have the ignition switch turned on first, etc. BE CAREFUL! DON'T TOUCH THE TWO WIRES TOGETHER OR LET ONE TOUCH CHASSIS, OR YOU WILL BLOW A FUSE...
Hope this helps with what you are asking about?
GOOD LUCK!
Southbound
But if you are talking about a 12volt DC voltage source like what feeds the cig lighter, or utility power receptacle, or vanity lights, etc. There are a few ways you can go about it.
The BEST way would be to get your hands on ANY kind of voltmeter. Any old cheapy type would do... it could even be an old Simpson analog meter. If you are trying to determine which wire is positive and which wire is ground (negative)... Take the negative lead of the voltmeter and touch it to chassis ground. Then take the positive lead of the voltmeter and touch each wire SEPARATELY. One wire will read around +12volts and the other lead will read zero volts or very near it. This tells you which wire is sourcing the POSITIVE voltage. THAT WOULD BE YOUR POSITIVE WIRE. The other wire would be negative.
If you can't beg, borrow, or steal a voltmeter... Find something small that runs off of 12volts. Get any automobile inside dome light or vanity bulb. Get a clip lead and attach one end to chassis ground, and one end to any terminal of the light bulb... Then touch each of the two wires (one at a time) to the other terminal of the light bulb. One wire will cause the bulb to light and one will not. The one that lights the bulb will be the HOT wire which will be your positive wire. The other wire will be the ground wire or negative wire. This assumes that the negative wire is at ground potential, or very nearly so. That should be the case with any power wire in the car... but again I don't know what you're talking about with a NEON bulb. NEON BULBS TAKE 90VOLTS TO LIGHT UP???? So either you've got some aftermarket gag with an unknown power supply that may or may not float from ground, or you have simply called it a neon bulb by mistake.
If you are talking about common 12volt power wires running throughout the TL, then my test methods should easily tell you which wire is which. Of course you will have to have power supplied to the wires for the light bulb or voltmeter test to work. So you may have to have the ignition switch turned on first, etc. BE CAREFUL! DON'T TOUCH THE TWO WIRES TOGETHER OR LET ONE TOUCH CHASSIS, OR YOU WILL BLOW A FUSE...
Hope this helps with what you are asking about?
GOOD LUCK!
Southbound
Pro
Joined: Feb 2002
Posts: 664
Likes: 1
From: staten island ny
Do you still have the plug? If you do you can just match up the wire with the stripe, and then follow it down. If its in the center its positive, if its on the side connected to the metal grounding tabs, its negative. Or you could use Southbounds method.
Chris
Chris
i just did it the easy way... connected it straight to the battery... it didn't work so i reverse the polarity then it worked... heheheeh thanks for ur help guys... i was too lazy to get out my volt meter and test... but so far i got 4 tubes installed... 2 left... i will post pics when someone lets me borrow their digi cam or i can find my camera under all its dust... thanks for ur help guys...
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