Overheating Help! | Testing Cooling Fans - Relays - Connections

now today we'll be talking about cooling fans now specifically on your late model vehicles you tend to have two speeds built into these fans there's a low speed and a high speed and there's a way you can test both of those speeds and if they're not turning on we can test the motor itself the fan motor we can test the harness connectors we can check the relays which happens to live over there in this vehicle so there's a couple of different steps we can take so if you have a problem with your vehicle overheating because the fans aren't turning on this will give you a really good idea on the steps involved the pinpoint where the problem is but right off the bat what you can do is start the vehicle start the air conditioning once you start the air conditioning the low-speed fan should turn on in other words these fans should kick on but it's at the low speed setting so let's first try that and we can then move on to the next step so once we turn on the air conditioner these fans kicked on right away but let's say you do this on your car and the fans don't kick on what do you do well let's go through the steps involved now if you just perform that test and nothing happens you turn on the air conditioning and the fans aren't kicking on let's first check the power source going to the relay in other words if you take a look on every vehicle you have a fan relay and as you can see you have number one number two and number three in this case we're just dealing with number one number one is your low speed relays two and three is your high speed which we'll talk about later so let's go ahead and remove this box this is where where the cover I should say this is where the relay lives so right here is number one relay and we need to remove it so I'm going to grab a flathead and very gently as you can see this car is 20 years old so this is very wobbly I really should tap a new a new line in here but that said just remove the relay be gentle be a little little cumbersome but right here is a tab we just want to gently pull it up just like that and there we go okay so what we're going to do is turn on the ignition key and test for battery voltage in other words we want to verify that power is getting to this relay if it isn't the fans won't kick on so to test that you need a multimeter which I'll show you in a moment now if you've ever used a multimeter you can purchase one of these twenty twenty-five dollars Sears Home Depot Lowe's Amazon your local auto parts store they all have them and the setting in this case we need V which is volts DC that's direct current okay so now we have the ignition key turn on and I want to verify that 12 volts worth of power is getting to this harness where the relay lives now if you don't know which harness to touch just you can test every one but essentially you want to make sure that you gain 12 volts worth of power and this vehicle is terminals 3-1 so if I touch this guy and this guy should get 12 volts worth of power and I'll give you a different shot in a moment so your red lead goes directly directly here okay black goes to ground which is any good metal point and we and we have 12 volts worth of power same with this guy right here 12 volts worth of power so this verifies that battery voltage is getting to this relay box or this harness connector we test the other guys just to show you no voltage very very small voltage this is what you want to see okay 12 volts 12 volts now if you're not getting power if you're not getting any power to the relay box you have to find the short chances are it's going to be between the cooling fan relay and the battery so somewhere the connection from here to here there's a there's a short and you got to find that out you got to dig it up but if this is turning out okay for you the next step is checking ground and let me show you on how you can do that now the next thing we're going to check is the harness connector for the cooling fan so in this case we have two cooling fans so we have to harness connector so just disconnect them the other one is right over here okay and right where my thumb is just to show you if I did that too quickly there's a tab push down the tab pull on the body don't pull on the wire pull on the body so again now we need the multimeter and this is the symbol that you want it looks like a Wi-Fi hotspot that's for continuity so we want to make sure that two points make a connection and what we're doing here is testing the wiring on the harness connector in other words if there are any breaks anywhere in the wiring so on this vehicle if I touch number one so there's four terminals here if I touch number one now it doesn't matter if it's positive or negative if I touch number one and then the other end of the multimeter the other probe goes all the way back this is again where the relay lives and if I touch terminal number five we should have continuity and we do so that verifies that we don't have a break here I'm going to do the exact same test also with this is fan number one we have to test fan number two same exact thing now obviously I can't show the multimeter and they're in the relay box but again when Terminal goes here the other one goes right to number five on the relay box and we have continuity so that verifies that we don't have any breaks in the wiring for the coolant fans now if you're not getting continuity here then you have to find the break which is going to be between the relay to the harness connector somewhere from here to here or from cooling fan number two there's a break and you got to find it it's that simple now let's say that this test also works for you now the next check the next test is actually testing the relay itself now the tester relay I have a separate video on that already I'm just going to splice it in again you need the multimeter and then the last step I'll come right back is testing the fans itself which will apply direct power right to the fans now we're going to test all three relays but this is how you can quickly do this test really on any vehicle if you take a look there's a diagram on top of the relay and all that this means is when number one in terminal number two is energized so in other words when it receives 12 volts worth of power numbers three and five turn on it's essentially a switch a relay that's all it is so right now there's no power being applied to this so terminals three and five back here are not connecting okay when you apply power to number one and two then three and five make a connection now how do you test that you can sometimes you can try by listening if there's a click but really the best way is to do a continuity test so what you want to hear something like this okay when we apply power so the next question becomes how do I apply power to terminals 1 & 2 you don't have anything you can use your car battery now that's a little cumbersome so what I'm going to use I have an RC battery pack this pushes out pretty close to 12 volts so I'm just going to grab alligator clips connect it to terminals 1 & 2 and we'll see if we have continuity if you're getting a little confused let me hook everything up and I'll show you how simple it is to test one of these and you can really do this type of relay test on any component on your vehicle so you want to test AC relays if you want to test grab this other one the cooling fan relays that we have here starter relays relays for actually you can hear it click well then you hear that now that's not always a sure sign that this is working correctly so keep the power there and now you just get this cleaned up a little bit okay so now we want to see if we have continuity so just take the leads terminals 3 and 5 and we should hear an audible alert and there you go hope and get a good connection there we go so that verifies that we have continuity this is working correctly now if you perform the relay test and the relays working the last step is testing the fan motor itself and to do that you just applied direct power directly to the fan so this is the wiring going directly to the fan this is the other wiring make sure you guys can see that right here yep for the fan number two so what we're going to use or do is apply 12 volts worth of power directly to this connector now you can use the car battery or in my case I'm going to use a a lipo battery pack this isn't for an RC car and it pushes out roughly 12 volts worth of power but all that you want to do is essentially get power from a 12 volt source directly to the fan so apply power so I'm just connecting essentially the battery to this connector to the motor that's it that's all we're doing here now once I connect the negative terminal here the fan should spin so here we go so here we go [Music] so there you go the fan is working and we'll do the exact same test with this guy [Music] and there you go so these are the steps that you need to go through to pinpoint where the problem is check the relay check the wiring check the motor itself so this is for the low-speed we'll do the exact thing a very very similar thing to test for high-speed now the test with a high-speed function on the coolant fans there really are two ways you can do it option one is you find the coolant temperature sensor so that's right here in this vehicle you can always tell because right here is the upper radiator hose that's where the coolant flows through so right there is a sensor you disconnect the harness connector and you attach a hundred and fifty ohms connector to the harness connector so you disconnected apply 150 ohms worth of resistance to the connector start the vehicle and that will kick the high speed function on the fence now I specifically purchased these hundred fifty ohm capacitors to do this test and I can't find them I have no idea where they went I just can't dig them up right now but there is another option and how to make this work so coming back to the wiring this runs directly to the fan motor we just did the test on how to test for the low speed when we applied 12 volts worth of power using the battery okay we just did this test but when we did the test we essentially touched one top terminal and one bottom terminal now to do the high speed we're going to touch both top part terminals and touch both bottom terminals so again I have to the top terminal I have the positive positive going to the top negative going to the bottom okay hopefully I don't blow anything up and here we go here we go here goes nothing and that's certainly faster so that verifies that the high speed is working here let me disconnect this okay so I'm not sure if you were able to pick that up but the high speed is certainly working on this fan motor but let's say you want to backtrack you want to see if the relays are fine you want to make sure to make sure that the wiring is in good shape let's go through the steps it's extremely similar to when we tested the low speed so just like we did with the low speed relay we want to test the relays as well as the connections going to the relays so I'm going to remove both high speed relays and let's see that the wiring and verify that everything is in good shape so now we're going to do the exact same test that we did with the low speed relay so here we have the two high speed relay inputs the ignition key is turned on positive goes to this guy negative goes to ground and we should see 12 volts worth of voltage let me just get my hand out of the way so you guys can see this hold on okay 12 volts the other one we need to check is number three okay 12 volts again if you're not sure you can touch different terminals but as you see we have essentially no reading or very very low reading but this is what you want to see 12 volts 12 volts same with the other guy terminal 1 12 volts terminal 3 12 volts ok so that verifies that power is getting to the relay box again if you don't see anything here you have a short between the box and the battery so now we need to test for continuity continuity is two points making a connection that's the Wi-Fi symbol on the multimeter so if you remember on the cover of the relay box it says radiator fan number two radiator fan number three so number two is referring to this fan right here this is the driver's-side fan number three relay is referring the passenger-side fan okay so two fans driver's side passenger side so we're first we're first going to test continuity for get my wiring here for the driver's-side fan so one terminal goes to number two that's the upper right-hand quadrant the other one goes to number five and we have continuity same with terminal number three that's the bottom left go ahead and touch number six on the relay box oh that's right here and there you go with continuity so this verifies we don't have any problem with the wiring if you're not getting continuity then you have a break between here and the relay box now let's test the exact same thing for the passenger-side fan but again now for the passenger-side fan we're testing this section of the relay box okay we have continuity again to number three and then to number six on the box and we have continuity okay now let me just change the camera now the next step is actually testing the relays itself again I have a separate video on how to test these I'll just splice that in right now and we'll come right back so here we have the high speed the high speed relays and same exact thing if you apply power to terminals 1 & 2 1 & 2 just look for this symbol if you apply power then terminals 5 & 3 make a connection and 7 & 6 both of them do same with this 5 & 3 7 & 6 so here we go applied direct power let's see if it clicks which it does well let's test it beyond that okay grab our multimeter here we go okay so that makes a connection let me zoom in here okay let me do that again so numbers three and five okay that's good and number six and seven okay that's working good same with this apply power the terminals 1 & 2 let me get this out of the way okay sorry about that so again we're just applying power again this is clicking you just make sure you guys can hear this okay and same exact thing number three and five okay six and seven that's it that's all it takes to test your cooling fan relays now if you test the relays and they're in good shape the last step is testing the fan motor which we've already done and we know that the fan motor is in good shape so if the fans aren't working these are the steps you have to go through again chances are if you're having problem with the fan it's coming down to the relay or most likely the fan motor itself it's sort of rare in a sense that these newer cars have a break somewhere unless it's just been sitting so long and you have gnats and insects and mice and birds is chewing at it at the harness connectors but that being said these are the steps you need to do so hope this helps someone out there if you like this please thumbs up subscribe and we see you next time [Music]

Channel: CarsNToys

Views: 913,743

Rating: 4.8082638 out of 5

Keywords: overheating, car overheating, truck overheating, cooling fans, cooling fan relay, cooling fan connector, leaking coolant, waterpump, bad waterpump, coolant color, thermostat, radiator, leaking radiator, radiator fins, radiator hose, coolant reservoir tank, leak test, mechanic, auto repair, auto repair help, auto repair diy, eric the car guy, chrisfix, jay lenos garage, doug demuro, autocar, mighty car mods, motor trend, regularcars, saabkyle04, tj hunt, the smoking tire

Id: 41GzoW4cR18

Length: 17min 51sec (1071 seconds)

Published: Sun Aug 27 2017