coolant temp sensor not reading
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New User
Joined: Dec 2008
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coolant temp sensor not reading
I had my lower rad hose blow out on me while driving the other day,got it home before i lost all the coolant,the question i have is now my temp gauge barely goes above cold.I tried testing it using a jumper wire to a ground with the key on and nothing,should'nt it have moved to the hot side?.Before the blow out it worked fine,could the mass loss of coolant at a fast rate damage the sensor causing it not to give a reading.the sensor itself does not leak,is there another way to test it?.
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Joined: Jun 2009
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I know you posted this a while ago. I'm assuming this is the sender unit next to the thermostat, and not the sensor over on the left side of the intake manifold.
You can test the sensor with a VOM. You should see a resistance of 3 to 5 Kohms across the sensor. If you jump the vehicle side of the sensor with a wire, the guage should go all the way to hot (with the key on, engine NOT running)
If you heat the sensor up with a lighter and measure across it, the resistance should DROP as the heat increases. mine went from 3.5Kohms to about 900 ohms resistance when I heated it up. so check the other lead and make sure it has continuity to ground. (if the gauge doesn't go to hot with a jumper, you need to do some homework on this side.) NOt sure what vehicle you are working on, but there may be a blown fuse as well.
you also need to check for voltage at the terminal. One of the leads should be 12V to gnd. Al
What engine is this for? (year, engine?) I actually broke my stock sensor when I was checking it and replacing the thermostat, and had a helluva time getting a new one. Ended up getting the CORRECT part finally from Rock Auto. I can send you the PN if you need it.
You can test the sensor with a VOM. You should see a resistance of 3 to 5 Kohms across the sensor. If you jump the vehicle side of the sensor with a wire, the guage should go all the way to hot (with the key on, engine NOT running)
If you heat the sensor up with a lighter and measure across it, the resistance should DROP as the heat increases. mine went from 3.5Kohms to about 900 ohms resistance when I heated it up. so check the other lead and make sure it has continuity to ground. (if the gauge doesn't go to hot with a jumper, you need to do some homework on this side.) NOt sure what vehicle you are working on, but there may be a blown fuse as well.
you also need to check for voltage at the terminal. One of the leads should be 12V to gnd. Al
What engine is this for? (year, engine?) I actually broke my stock sensor when I was checking it and replacing the thermostat, and had a helluva time getting a new one. Ended up getting the CORRECT part finally from Rock Auto. I can send you the PN if you need it.
