Wired backwards? Engine coolant temp sensor... please help 1986 5.0
- Thread starter Phdiesel
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That’s not true... geez... it’s not just a resistor... if you get it backwards the car will think it’s hot when it’s cold and cold when it’s hot and it will adjust fuel accordingly... Please stop wasting peoples time and stop answering questions you know nothing about...
I assure you he knows what he is talking about.
It appears you may be misinformed, from where I don't know.
If he is wrong please provide info showing this.
My Apologies. Technically it's a 2-wire thermistor which has no polarity and functions off a 5V reference voltage.
I guess we will wait for someone who really knows to come along.
Actually you need to go read the paragraph again buddy!!! All of you!!! It actually says in section 240 as temperature increases resistance decreases!!! Read the paragraph again that’s exactly what it says so you are wrong. You don’t even know what you’re reading.Go read it yourself and come back and tell me it doesnt...
For all of you to think he is right and I’m wrong look at the attachment that he even sent me. You don’t even understand what you’re reading
Do you even know how to read that chart??? That’s a negative coefficient sensor buddy. It’s very easy to understand that because it tells you. As temperature increases resistant decreases. That’s what the chart says can’t you read a high temperature equals low resistance that’s a negative coefficient. Re-read the first paragraph yourself I’ll post it again.. it’s not “just a resistor”
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It’s very clear that it’s a NTC sensor... it says so. And if you’re able to read that chart you sent youd see that it is as well... not arguing but you say it isn’t and the chart and paragraph actually says it is... sorry but, you guys are confused... “as temperature increases resistance decreases” that’s not “just a resistor” Because if you turn it around backwards you don’t get the same reading. Try it for yourself. But you didn’t help me out providing me with the schematic in which my problem is fixed... and for all of you that think I am wrong, go swap the wires on your sensor and come back and tell me your car doesn’t run like 
....
....Attachments
ok, while I'm not a highly trained automotive tech, I will say your attitude (whether you are wrong or right) is not making you any friends, people come here looking for advice, not to be berated, that said, if you are smart enough to know how this sensor works you should be smart enough to figure out how to wire it. 
I don't see any wires on this sensor, also on the one at rockauto,
I don't see any wires on this sensor, also on the one at rockauto,
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@Phdiesel
Ummmm, what a rant dude. You're not going to get much help around here acting like, but what the heck, let me try to help explain this to you.
BTW, what @Mustang5L5 said is absolutely correct, you can wire it either way. Since you seem to want specifics, it's technically called a NTC thermistor type sensor. A thermistor is a type of resistor. The Mustang ECU sends a 5v reference signal to the sensor and the resistance value through the sensor (depending on temp) causes a voltage to be sent out the other wire that is received by the ECU (just like the paragraph you circled). And you are correct, a NTC thermistor's resistance goes down as the temperature goes up. Also, as you can probably tell by the chart you are referencing, the resistance value is not linear to temperature change.
Here's the kicker, you can wire it either way because it's a thermistor (resistor) and will drop voltage either way. It doesn't care which way you wire it, it's a resistor and electricity can flow either way (no polarity). We're not talking about a diode here.
Look up "does it matter which way I wire a thermistor" and check yourself.
Edit, in fact, here ya go. Just click here and read.
Google Search "does it matter which way you wire a thermistor"
Ummmm, what a rant dude. You're not going to get much help around here acting like, but what the heck, let me try to help explain this to you.
BTW, what @Mustang5L5 said is absolutely correct, you can wire it either way. Since you seem to want specifics, it's technically called a NTC thermistor type sensor. A thermistor is a type of resistor. The Mustang ECU sends a 5v reference signal to the sensor and the resistance value through the sensor (depending on temp) causes a voltage to be sent out the other wire that is received by the ECU (just like the paragraph you circled). And you are correct, a NTC thermistor's resistance goes down as the temperature goes up. Also, as you can probably tell by the chart you are referencing, the resistance value is not linear to temperature change.
Here's the kicker, you can wire it either way because it's a thermistor (resistor) and will drop voltage either way. It doesn't care which way you wire it, it's a resistor and electricity can flow either way (no polarity). We're not talking about a diode here.
Look up "does it matter which way I wire a thermistor" and check yourself.
Edit, in fact, here ya go. Just click here and read.
Google Search "does it matter which way you wire a thermistor"
Well... my attitude?ok, while I'm not a highly trained automotive tech, I will say your attitude (whether you are wrong or right) is not making you any friends, people come here looking for advice, not to be berated, that said, if you are smart enough to know how this sensor works you should be smart enough to figure out how to wire it.
I don't see any wires on this sensor, also on the one at rockauto,
My attitude? Are you a snowflake that can’t tags direct talk? The first response was a snide one and I don’t special that... I actually know what I’m talking about and I, don’t like pale who don’t talking me I’m wrong without a little bit of info.. as you see, I tried to back mine up but everyone wants to discredit what I’m saying... all i I wanted was help... not off the wall comments... I appreciate your words but also, I’m trying to get understanding here and people are giving angers that aren’t really true.. thank you, I’ll try to do better, maybe others can do so to ok...
You also know I’m right....
LMR agreed with me but they don’t have the pigtail... I came in here wanting to know of anyone else had this sensor I did... not to be told that it wasn’t something that you and I both know it is... LOL... these guys put me down acting like I don’t know what I’m talking about... All I Gotta say each and everyone of you that think I’m wrong take your sensor in your resistance meter and hook up to it and throw it in hot water see what the reading is then turn the leads around and do it again and I swear to God you get a different answer. Case closed you guys need to do your research
You're wrong, but you're allowed to believe whatever you want. Us guys have worked with and replaced these sensors for years and know how they actually work. If you know how the eec-iv works (or most any other ecu or control system) you'd also understand this. But to each their own, enjoy!
@Phdiesel
And just because I'm in a the mood to drive home how wrong you are because of the way you are addressing some very well known, knowledgeable, and respected members, here is a little real world test to drive the point home. Took my 2 minutes in my garage.
So here is the exact sensor you are talking about (2-wire, ECT temp sensor from a 5.0, Ford part # DY1145, 1984-1995 mustang). I measured this at room temp which is around 55 degrees in my garage.
Then I reversed the polarity of my test leads on my multimeter. Go figure, the exact same reading! (within measurement tolerance of course)
So then, according to your logic, if I would introduce some heat into the sensor and measure, I should get a drastically different reading when I reverse the polarity of my test leads? Right?
Reverse the test leads, and MAJIC! It reads about the same (sensor continued to soak some heat from the heat gun while I was getting the second measurement). But also notice how the resistance value went down, because it got hotter, just like a NTC thermistor should.
Around here, we treat our members with respect. You'll have to learn you can't assume the attitude of someone by the way you interpret their words online, otherwise you're going to have a really hard time on the internet in general. I have never seen any of those guys that responded to you put down anyone (that didn't absolutely deserve it). And after reading what you copied and posted, I can definitely tell you they were trying to help you and you took it the wrong way. Maybe take a step back and take a deep breath next time and try to approach it in a more civil way.
And just because I'm in a the mood to drive home how wrong you are because of the way you are addressing some very well known, knowledgeable, and respected members, here is a little real world test to drive the point home. Took my 2 minutes in my garage.
So here is the exact sensor you are talking about (2-wire, ECT temp sensor from a 5.0, Ford part # DY1145, 1984-1995 mustang). I measured this at room temp which is around 55 degrees in my garage.
Then I reversed the polarity of my test leads on my multimeter. Go figure, the exact same reading! (within measurement tolerance of course)
So then, according to your logic, if I would introduce some heat into the sensor and measure, I should get a drastically different reading when I reverse the polarity of my test leads? Right?
Reverse the test leads, and MAJIC! It reads about the same (sensor continued to soak some heat from the heat gun while I was getting the second measurement). But also notice how the resistance value went down, because it got hotter, just like a NTC thermistor should.
Around here, we treat our members with respect. You'll have to learn you can't assume the attitude of someone by the way you interpret their words online, otherwise you're going to have a really hard time on the internet in general. I have never seen any of those guys that responded to you put down anyone (that didn't absolutely deserve it). And after reading what you copied and posted, I can definitely tell you they were trying to help you and you took it the wrong way. Maybe take a step back and take a deep breath next time and try to approach it in a more civil way.
Here's the thing... You came here looking for advice and got advice and didn't like it. You know more than everyone so just go do what you think is right. In my experience i asked a similar question and then just wired up my sensors without concern for polarity and unless I'm extremely lucky everything in my build has been 100% fine. Feel free to check it out and see that i have a significant amount of money in it and it runs awesome!
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