Using an ohm meter and temperature sending unit
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Joined: Nov 2010
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Using an ohm meter and temperature sending unit
Can someone explain how to use the ohm meter for testing the temperature sending units I have. I am going to try and find one that come close to the readings I have seen in the forums.
Thanks
Thanks
Pro
Joined: Nov 2010
Posts: 602
Likes: 32
From: Old Bridge, NJ
Connect one lead to the connector of the sender and the other lead to the brass body of the sender, drop in a pot of water and start heating the water. Use a thermometer in the pot to observe temperature. Write temperature vs. resistance reading all the way up to boiling.
Once you do this, go to Radio shack and buy a resistor assortment. Take the various resistors and connect them from the lead in the car that connects to the sender to a ground (any metal on the car). Turn your key on and observe where each resistor places your gauge. Typically on our cars the range of resistance is 50 ohms to 300 ohms, but they do vary.
Compare what you measured in th epot versus what your gauge wants and you will know if you are good with the sender you chose.
If you are off a little, but teh sender is working (i.e., behaves linearly with temperature) thenyou can add a series resistor in the lead to the sender to adjust it for your gauge.
Good Luck.
Once you do this, go to Radio shack and buy a resistor assortment. Take the various resistors and connect them from the lead in the car that connects to the sender to a ground (any metal on the car). Turn your key on and observe where each resistor places your gauge. Typically on our cars the range of resistance is 50 ohms to 300 ohms, but they do vary.
Compare what you measured in th epot versus what your gauge wants and you will know if you are good with the sender you chose.
If you are off a little, but teh sender is working (i.e., behaves linearly with temperature) thenyou can add a series resistor in the lead to the sender to adjust it for your gauge.
Good Luck.
Last edited by njfl; Oct 20, 2011 at 02:23 PM.
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Burning Brakes
Joined: Feb 2011
Posts: 850
Likes: 12
From: Shakopee MN
Note that I'm using the WT203Z, not the WT203. I think Roger had found a difference. I got mine from Advance Auto. It may not be 100% accurate but it's pretty damn close, a lot better than the one I bought from Paragon Corvette.
