Snake
Mopar Nut
The intake is not on the car yet,is there a way to test that sensor befor I install the intake and how.Thanks.
temp sensor
- Thread starter Snake
- Start date
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mopar340dave
Well-Known Member
To test the gage you can turn the key on and then ground the wire that goes to the sensor...your gage should max out.
Your temp sensor is actually a variable resistor called a thermistor. You can test the sensor with an ohm meter. The normal resistance on an engine at 50 to 80 degrees F = 2,200 to 2,700 ohms. As the sensor temperature DECREASES, the resistance value will INCREASE and vice-versa. Take a coffee cup full of water and nuke it until it gets very hot (bubbling). Check the ressistance again now with the end of the sensor in the hot water. If the sensor is good it should have decreased the resistance.
You put the + lead to the wire hookup and the ground lead to the body of the sensor or ground wire...depending on what you have. By my memory, ours is a single hot, body ground.
I am assuming we are talking about the temp sensor for your gage, not the one that turns on an optional electric fan. the one for a fan is actually just an on/off switch activated by a particular temp.
I hope this helps....I'm going by memory here....
Your temp sensor is actually a variable resistor called a thermistor. You can test the sensor with an ohm meter. The normal resistance on an engine at 50 to 80 degrees F = 2,200 to 2,700 ohms. As the sensor temperature DECREASES, the resistance value will INCREASE and vice-versa. Take a coffee cup full of water and nuke it until it gets very hot (bubbling). Check the ressistance again now with the end of the sensor in the hot water. If the sensor is good it should have decreased the resistance.
You put the + lead to the wire hookup and the ground lead to the body of the sensor or ground wire...depending on what you have. By my memory, ours is a single hot, body ground.
I am assuming we are talking about the temp sensor for your gage, not the one that turns on an optional electric fan. the one for a fan is actually just an on/off switch activated by a particular temp.
I hope this helps....I'm going by memory here....
Snake
Mopar Nut
Thanks Dave ya it the gague sensor,I will give that a try.
mopar340dave
Well-Known Member
cool, glad to help.
scott mattingly
Well-Known Member
Mopar340dave(or anyone),
Using this old email to launch a related request for help.
I just installed a new stroker motor back in my 74 duster a few weeks ago. After struggling with header/exhaust connections and a few oil leaks, everything (almost) is working fine and I now have a few hundred miles on the engine.
The almost...is that my factory temperature gage started to act "wonky" when first starting engine and now has completely quit. By wonky I mean that it initially pegged to full right (off the scale) on start up and then would move a little bit to the left (cooler) range on gage after driving for 10 mins. or so. That persisted for 3-4 trips and then it simply pegged at full left(off the cold end of the range) and stays there. (I've been measuring temps with a gage built into my radiator cap and they have been at around 180-190-deg whenever checked).
Some background:
--All other gages(ammeter, fuel, speedometer, oil/brake lights) work the same as they did before installing the new engine.
--New intake and old intake were both aluminum
--I was initially using my old sensor in the intake but decided to replace it with a new one(Gage remained INOP and stays pegged all the way to the left)
--I measured voltage from the sensor wire to ground and with key turned on it is at 12Volts.(not sure what it should be?)
What other troubleshooting steps can/should I take?
---It's certainly possible that the dash gage has simply gone bad(it looks like the original 1974 unit) but I want to confirm before replacing it.
-THX Scott
Using this old email to launch a related request for help.
I just installed a new stroker motor back in my 74 duster a few weeks ago. After struggling with header/exhaust connections and a few oil leaks, everything (almost) is working fine and I now have a few hundred miles on the engine.
The almost...is that my factory temperature gage started to act "wonky" when first starting engine and now has completely quit. By wonky I mean that it initially pegged to full right (off the scale) on start up and then would move a little bit to the left (cooler) range on gage after driving for 10 mins. or so. That persisted for 3-4 trips and then it simply pegged at full left(off the cold end of the range) and stays there. (I've been measuring temps with a gage built into my radiator cap and they have been at around 180-190-deg whenever checked).
Some background:
--All other gages(ammeter, fuel, speedometer, oil/brake lights) work the same as they did before installing the new engine.
--New intake and old intake were both aluminum
--I was initially using my old sensor in the intake but decided to replace it with a new one(Gage remained INOP and stays pegged all the way to the left)
--I measured voltage from the sensor wire to ground and with key turned on it is at 12Volts.(not sure what it should be?)
What other troubleshooting steps can/should I take?
---It's certainly possible that the dash gage has simply gone bad(it looks like the original 1974 unit) but I want to confirm before replacing it.
-THX Scott
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