How to diagnose a bad temperature sensor. 2000 Ford Focus ZX3

[@luisfernandonavarro910]

Bro.... I spent hours trying to find the problem till I saw this video, thanks for the info. It also works for 2008 Ford Escape 👍🏼

[@dr.auggie1109]

Thanks for letting the rest of us know brotha

[@jimdeeny2892]

Thanks for the input, the coolant switch is in such an easy spot to replace, I did it in less than 2 hours.

[@alexgardiner3977]

Thanks for the video bro I was wondering why my cooling fan was running so high keep up your good work

[@terryautrey7233]

My 2001 Ford Focus was doing the same thing with the fans not working when the AC is off. I did change the temperature switch but the overheating wasn't stopping. Then I checked the resistor that goes into the fans. The resistor wires goes to the temperature switch. The connection point of the resistor was fried. So you will have to buy a kit and cut the wires and splice them to put the new resistor on. All my overheating problems went away. If this happens to anyone, it could be one or the other or both.

[@d.j.9961]

I changed the temp sensor, water pump, timing components, thermostat & housing, all the cooling fan relays, cooling fan solonoid, then, the fans! Nothing fixed the issue. When I unplug the cht sensor, the fans come on so, for a while, I ran it with the temp sensor disconnected & it killed my alternater! I ended up splicing into the brown & white wire for the cht/temp sensor & running a toggle switch inside the car & it has worked, allowing me to turn the fans on & off! One of the cylider head temp sensor wires is 12v & the other is a 5v computer reference wire. I forget which one I used, it's the brown wire that I have ran a toggle wire to. After 1-3 years, the temp sensor started acting up so, today I am replacing the temp sensor again & when I have time, I will test the wires to see which is 12v & which is 5v reference & possibly switch them/ connect the toggle to the other wire! This has allowed me to cycle the fans manually & keep my focus cool!!!

[@dappa211]

Was the gauge working when you first changed the temperature sensor?

[@chrispynaples]

Bro thank God for you I've been having this problem for awhile now

[@Gemminttrading]

Thank you for uploading this video. I have been chasing after this problem for over a year. I have an 03 wagon with the same 2.0 DOHC engine. It was getting so hot and building up so much pressure it actually cracked the reserve tank

[@Pentagonmechanicalservices]

+Cincinnati Cars wow my brotha My reserve tank cracked too because of this issue But thank God we figure it out

[@Gemminttrading]

Jonatan Rosales how hard was it to replace that temp sensor?

[@Pentagonmechanicalservices]

The hardest part would be removing the sensor because is stuck in there because of the heat cycles the vehicle has gone thru But installing it is more easy Tightening the new sensor will be a bit of a challenge because you will need a open wrench 🔧 to tighten and there is not a lot of room I did it from the top

[@Gemminttrading]

Jonatan Rosales thanks bro. I gotta get this ✔

[@Pentagonmechanicalservices]

Cincinnati Cars good luck my brother and anything ask her

[@jimmarchant1056]

Very helpful 👌 don't keep it like this on your cars or you'll burn you're autonator out, use this to check for a bad temp switch. Works a treat

[@quietwon8992]

Isn't this sensor for the temp gauge in dash panel? It flattens out to cold when u unplug this sensor. Are you sure this is what also turns the fans on???

[@dappa211]

Does that control the gauge reading of the coolant? Am having similar issue but my gauge seems to work fine. The fan only works wity the a.c but spins too slow to be efficient. My model has only 1 fan

[@Pentagonmechanicalservices]

Could be an issue with the relay, if the problem persists, then it could be the fan the issue.

[@1Dudey1]

Thanks! Worked exactly as you showed

[@Daddychill945]

Why is the check engine on and what problems have you had when you had it ty

[@kylelasko9973]

Thanks bro...I’ve been going over everything on my engine which is a 2.0 zetech dohc and had the same exact problem.... anyway after watching this video I went out on plug that started the car and sure enough the fans kick On....I appreciate it bro

[@jimmarchant1056]

Same here, good tip 👌 thanks dude

[@ubot982]

thanks for the tip .. after 2 busted hoses and the plastic pipe thing i cut one of the wires and am now running a toggle switch for the fan when i want it on. just a quick fix till spring then i will change out the sensor.

[@josecarlosvaliente4100]

Good idea

[@akalksander9184]

I'm thinking of doing the same thing.

[@d.j.9961]

I replaced every part of the cooling system on my 03 focus dohc zetec! The thermostat & housing, water pump & all timing components, new cooling fan solenoid, new fans, all the relays, the cylinder head temp sensor & yet, the fans DO NOT CYCLE OR COME ON AT ALL! My A/c does not work so, I could not test it that way however, when I unplug the cht SENSOR-BOTH FANS COME ON SO, I SIMPLY LEFT THE CHT (CYLINDER HEAD TEMP SENSOR)- UNPLUGGED (WHICH FRIED MY ALTERNATOR!) TO MUCH OF A LOAD! ULTIMATELY I ENDED UP SPLICING INTO ONE OF THE CHT SENSOR WIRES & RUNNING A TOGGLE SWITCH INSIDE THE VEHICLE! IT HAS WORKED BUT, IT DID CAUSE PROBLEMS WITH THE SENSOR AFTER 1 OR 2 YEARS! Since it is only $20.00, I would rather replace the temp sensor when needed rather then overheat since I cannot correctly diagnose the issue. It must be in the wiring or the ECU! At least I can turn them on & off & not have them run constantly/ putting such a drain on the alternator! Today, I am replacing the cht sensor again!

[@quietwon8992]

R both fans suppose to run when a.c. is off??

[@Todorstefanovvk8]

This is the same with mk1 st170?

[@quietwon8992]

I just installed new alternator.wish I'd known this. If that is the problem. That's a lotta work .

[@mvpbilly]

okay here is my car problem with my 02 FORD FOCUS SE 2.0 ENGINE, the high fan only turns on when the ac is ON, and also when im driving and the temp goes up. but on IDLE, it doesnt turn on. what could be the problem? the fuses are fine, the relay seems fine, the high fan connector has a lilttle burnt but still working.. IDK where to look now, 3 mechanics of mine cant figure out the problem. Please help me. Thanks!!

[@Pentagonmechanicalservices]

It could be the temperature sensor that is located behind Is really complex and difficult I changed it and I fix my issue but it could be different in every case The part is like 25 bucks I think I got it at pepboys

[@godson3160]

Hi my Engine smokes from exhaust manafold and smells of burning inside care when heaters are on. Please could you help.. 🙏🏾

[@FullTruthSeeker]

I had an acorn from my shade tree fall in between the exhaust manifold and heat shield. It smoked for a couple of days. Some years ago the squirrels kept trying to build a nest on top of our Jeep engine. The point is it might not be mechanical. If it smells like oil though then it might be time to replace the valve cover gasket. That is a job more tedious than complex.

[@hectoralvarado4586]

When you unplug the TCS radietor fan stay direct so you need to replaces tcs asap

[@Charles-ei6hg]

Is this related to p1299?

[@arnelrebenito7227]

Hey mate, i have some issue on my 2015 ecosport here in Manila (i have it for almost 3 years now), and suspect its the temperature sensor also that is causing the Fan to run continuously when AC is on.. Like after maybe a few minutes switching the AC, the fan kicks-in continuously and it won't stop until i turn off the AC again. i remember before it usually switch on and off when ac is on when ac is on, i remember maybe about 20 to 39 sec it use to turn off and on the fan not like today. i have my resistor block check by ford and they its in normal, but i argue that thats not how it behaves before, it use turn on and off. The technician also saying that before ecosport has only 1 fan(radiator fan) so it has to continuously run, he say, but i still argue that that's not how it works before. MY ac still works very well no issue at all, just abit worried on that radiator fan continuously running.

[@keseyoke]

thanks for that trick man! I just realized why my car is overheating in slow trafffic.....before I didn't do it....so does this means if I disconnect it and the fans go on is it the sensor bad and needs to be replaced?

[@Pentagonmechanicalservices]

+keseyoke yes the sensor is bad. Because even so it overheats and the fab doesn't work, then the sensor is bad. Plus the sensor is not expensive so is better to give it a try in changing it. Let me know bro if it works!

[@spacex2323]

Totally good job

[@albertofavela3127]

My car does not show the temperature, is this the sensor that I should change?

[@mvpbilly]

and also is it hard to replace the sensor? where is it exactly?

[@Pentagonmechanicalservices]

Paulo Ramos it’s kinda tricky but it can be change with some practice

[@kingdaniel3519]

On the Zetec, it's underneath the intake manifold. Easier to get to from underneath.

[@pokemongocoin1268]

Daniel Bell my zetec 1.4 is between cylinder 2 and 3

[@Pentagonmechanicalservices]

+Paulo Ramos is not hard to replace it But you need to have a wrench that has a opening so it can be a little easier when installing the new sensor It’s a 15 mm by the way

[@terryautrey7233]

To me it was easier to take the belt off and do it from above. Then there's two bolts on the alternator. Loosen and take out the front Bolt. The back bolt, all you have to do is loosen the bolt and tilt the alternator up. This will give you enough room to get your hand in the back where the temperature switch is located.

[@jayday5448]

my 2003 focus fans started working soon as I unplugged now I kno what I need

[@Pentagonmechanicalservices]

+Jay Day thank God this video helped you my friend

[@turuzapetewon2058]

When you turn you ac on..did the fan work?

[@Pentagonmechanicalservices]

Turuzà Petewon no it didn't 😢

[@turuzapetewon2058]

Jonatan Rosales thanks..thanks again for this video..it helps alot

[@jamesbuck3818]

OOOH That Poor Z-Tech..😮 She needs AMZOIL BAD!

[@ApaulloYGO]

The fact that you don't have a heat shield can cause an overheating issue or can ruin the fans

[@robestey5628]

Thank you

[@d.j.9961]

I have a 03 focus w/ dohc zetec vin-3 motor & I have replaced EVERY SINGLE PART! THE LIST IS WAY TO LONG TO LIST BUT, on my cooling fan issue, I replaced the coolant head temp sensor, cooling fan solenoid & wiring harness, I tested the fans & they work when I run 12v to them yet, I replaced the fans anyways, also, I replaced the green 70 amp low speed relay, also, the 2 black relays & since the grey hi speed fan relay is the same as the ignition relay, I swapped them, STILL, MY COOLING FANS DO NOT CYCLE OR COME ON AT ALL! My a/c doesn't work, so I don't have that luxury! I figured after replacing every part, it would be fixed but, NO! WHAT I CAN SAY IS, IF YOUR TEMP GAUGE WORKS THEN, THE SENSOR IS OK, MAYBE NOT PERFECT BUT, IF IT WORKS, IT WORKS, CHECK THE COOLING FAN SOLONOID THAT IS IN THE FAN & INSPECT THE WIRING ONE WITH A ZETEC WHO'S FANS DON'T CYCLE, YOU HAVE OPTIONS! ONE CAN SIMPLY DISCONNECT THE CYLINDER HEAD TEMP SENSOR & THE FANS WILL RUN CONSTANTLY- WHEN I DID THIS, IT FRIED MY ALTERNATOR! SO, I CUT ONE OF THE 2 WIRED THAT GO 2 MY HEAD TEMP SENSOR & EXTENDED BOTH ENDS OF THAT CUT WIRE, ROUTED THEM UP & OUT OF THE WAY & SECURED THEM TO THE FIREWALL & RAN THEM INTO THE CABIN & CONNECTED THEM TO A TOGGLE SWITCH, MOUNTED INSIDE MY FOCUS! NOW, WHEN MY CAR GETS WARM, I CAN TURN THEM ON & OFF & NOT HAVE TO LET THEM RUN CONSTANTLY/ FRYING MY ALTERNATOR! There is also a way of grounding out the low speed relay which causes the fans to run constantly. id rather have control of when my fans are running & how much of a load I am pulling from my charging system! I also have a amp & subwoofer & running my system & cooling fans on a 110-120 amp alternator can fry it within months! So, there are options! some people have luck with replacing their head temp sensor, cooling fan solenoid & wiring harness, cooling fans, water pump, thermostat & housing, I DID ALL OF THOSE REPAIRS & REBUILT THE LOWER END OF MY MOTOR & STILL, THE SAME ISSUE SO, I REN A TOGGLE SWITCH & KKEP MY EYE ON MY TEMP GAUGE! I AM CONSIDERING A DIGITAL READ OUT FROM AMAZON!!! IV HEARD THAT THE THREAD PITCH IS MM10X1.25 OR 10X1.50 ON THE FOCUS HEAD TEMP SENSOR? WISH I COULD FIND A SINGLE WIRE HEAD TEMP SENSOR TO RUN A AFTERMARKET COOLING FAN CONTROLLER. IF ANYONE FINDS A SINGLE WIRE SENSOR, PLEASE MESSAGE ME?????

[@t238]

this happened to me 2000 miles from home - it turned out to be my fan connector - connector just burns out - check ur connector to fan assembly

[@terryautrey7233]

I had the same problem. I changed the temperature switch but that wasn't the issue. Change the resistor on the exhaust fan. Look at the connector for it and take it apart it's probably fried. When I replaced it my exhaust fan started working every time with no more overheating issues.

[@alanmartinez4438]

Changed the sensor stil don’t work also change the fan resistor still nothing

[@Pentagonmechanicalservices]

Have you tested your fans? Maybe the fans are bad

[@SamiKrasniqi]

Do not do this , there are to many belts and moving parts for fingers to go near , there are other ways to check this , this is hacking that can cause you fingers detached .

[@Pentagonmechanicalservices]

+sami krasniqi thank you for your cautions my brother Is better to do unplugged and plug with the car off

[@dondeeman]

My fans don't eve turn on when the AC is on

[@Pentagonmechanicalservices]

Have you checked the related fuses? If so, what about a multimeter tool to make sure there is power going into the fans

[@EnjoyCalculus]

you said these cards dont have a temperature sensor but you showed some wire near the coolant reservoir and said its a temperature sensor?

[@careyracing6057]

Its a cylinder head temp sensor not a coolant temp sensor, on this car it uses that sensor to tell what temp your engine is.

[@jamesbuck3818]

TRUST ME..😊

[@MartinHernandez-qs7wz]

Disconnecting this, caused my resistor to glow up red and burned...

[@BryanJones]

Sheeeeeeesh :C

[@sharonvought3365]

Larry vought