rjbrown87

Please any suggestions helps.... My car overheats there is coolant in the radiator and in the reservoir.... I changed the thermostat that's on the same side as the alternator... The car temp gauge goes up as I drive sometimes it goes up then goes back down to the mid point... The fan on the passenger side comes on but not on driver side... Please help

alanfury75

Sounds like you need to replace the fan. Have you checked for leaks under the car?

rjbrown87

There are no leaks... Are both fans suppose to come on someone told me one was for the radiator the other fan for a/c

nestorlugo

iTrader: (11)

yes both should be on

They told you wrong ,I hope it wasn't a nissan tech after you payed $100+ for them to look at it ...you should change the fans and see if it still overheats...

FanaticMadMax

if the fan on one side is not coming on, possibly a blow relay, since there's two relay for it, for Fan 1 and Fan 2, whenever you turn on the a/c both fan should kick in, but if one not coming on. possibly the motor is burn out, you can replace the motor, but you can test see if the motor is out, is by simply unplugging the harness, and if you have two alligator wire clip and clip on the the plug on the fan from your 12v battery and see if it comes on, if it doesn't then the motor is out.

alanfury75

It could be a thermostat issue... but obviously, test/check the fan connections and motors to verify they are working.

johnsonzx77

Both fans should come on, and thats probably the issue. On the other hand, you might also have gotten some air in the system while replacing the t-stat. Try bleeding the air out.

Maxima577

My car used to do the same thing, i replaced, radiator,fans,thermostat. Now its mint, try any of those things,maybe your fans stopped working,or you have air in your cooling system

Maxima577

Replace fans - problem solved!
(Had same problem!)

Nelsito65

The fan on the driver side should come on first as the car heats up. The one on the driver side usually comes on when you turn the A/C. At that point both of them should be working. It looks like your driver side fan went bad. Sometimes replacing the fan assembly makes more sense than just replacing one fan or fan motor.

DennisMik

iTrader: (2)

Nooooooo. Both fans are controlled by one wire from the ECU. In the case of low speed, ECU pin 35 connects the energizing coil of Cooling Fan Relay #1 to ground. Cooling Fan Relay #1 has 2 sets of contacts in it, one set for each cooling fan motor. It is a somewhat similar design for fan high speed operation.

But each cooling fan motor has its own fuse, so it's possible for the fan motor to be good and not run.

VenomsMax

I have owned this car for years and have not opened the cooling system so I know its not air in the system. Same issue except my drivers side fan comes on when temp gauge is way up but doesn't appear to drop the temp to a normal operating temp on the gauge. When i kick the defroster on the pass side fan kicks on also.

Any ideas for my case?

BronxSleeperMax187

Whats way up?

DennisMik

iTrader: (2)

You've never looked at the level but you know it is OK. Sorry man, I don't believe that psychics are worth a damn at diagnosing car problems.

Take off the radiator cap (when the engine is cold) and look in the radiator. The radiator should be completely full, no air at all.

You have 2 problems.

1) The fact that the fan does not turn on until the gauge is registering high could be caused by 2 things. Low coolant level or a bad ECTS (Engine Coolant Temperature Sensor).

2) Both radiator fans are supposed to come on together. Start the car and turn on the a/c. Both fans should be running. If a fan is not running, it is bad and needs to be replaced.

And the part about turning the defroster on... I'd have to see it to believe it.

VenomsMax

I actually figured out the problem, but way up would be between the first and second line next to H.

My car is not actually overheating the sending unit for gauge is reading improperly, with scan tool hooked up ECT never reads higher then 203 degrees. At 203 fan kicks on and cools car down to around 195 using a IR thermometer checked at thermo housing temps are close to the same. Gauge reading almost to the first line in the H end of the spectrum.

So would appear all is well minus what the gauge is doing.

VenomsMax

Sorry i didn't type it out but the first thing i did was check the system to make sure it wasn't low on coolant after the car cooled down of course, which it wasn't low at all in fact.

According to your two problems listed....they're faulty....

First using your windshield defroster activates your a/c compressor. Both my fans operate and function, at the time i checked just happened to not be both operating at the same time....

Read prior post I found the problem... vehicle isn't actually over heating

Thank you for reading and trying to help though appreciate it.

DennisMik

iTrader: (2)

While I mis-understood the part about the defroster, I did not mis-state the part about both fans running at the same time.

Both fans should always run at the same time. If you ever have only one fan running, you have a problem.

When the ECU determines that the radiator fans need to run, it applies a ground to pin 35. The wire connected to pin 35 is the energizing coil for Fan Relay 1. When this relay energizes, it sends 12 volts to both radiator fan motors, the low speed winging.

When the ECU determines that the radiator fans need to run in high speed mode, it applies a ground to pin 36. This causes Fan Relay 2 & Fan Relay 3 to energize and send 12 volts the each fan motor's high speed winding.

VenomsMax

Good to know I'll check it out this weekend, I'm just glad I'm not actually over heating.