Cooling fans will not turn on

The a/c has been removed and has a bypass pulley, however unplugging the CTS and/ or turning on the a/c has not effect on the fans.

The fans still do not turn on.

What is litre size of engine? How hot is the engine temp reaching? Some fans won't even turn on till about 225 degrees F.

The temp was to 260 degrees, no fan turned on with or without the CTS plugged in. Is it possible the PCM has failed?
I have also noticed that the alternator is not charging the battery at idol at this point also.

At this point, if the battery is down and the charging system isn't working, you can't check anything. We are just spinning our wheels.

Will charge battery, what else should I be looking for, and the liter size is 3.8L. I will be checking to see the out put of the alternator.

Have you checked the fuses?
Did you check for battery voltage at the relays?

I checked all the fuses and I checked for resistance from the plug to the relay and it checked out okay. I have not checked the voltage at the relay as of yet.

You need to check for voltage to understand if it is power supply fault.

I do have voltage to the relays, I tested alternator and it is reading 11.56V I will be checking to make sure it is connected correctly and having it tested. If the alternator is not working correctly then there is not enough power being sent to the relays to have them turn on right?

Just out of curiosity which wire from the four pin connector should be connected to the red wire in the harness?

The alternator showing 11.56 volts means it is not charging correctly. It should show between 13.5 to 14.5 V.

Red wire should be connected to terminal marked " L ".

I finally got it put back together. I connected red wire to terminal L and it still is only reaching 11.50V Is there something else I should be looking for? Had alternator tested and it passed the test. Should I have it tested again?

Get the alternator tested again

If it comes back okay is there something else I should look at?

Check the wiring and the computer controlled of the alternator field generation circuit-

Is the voltage at alternator main mast 11.5v as well?

It didn't matter what connector wire I used all of the gave a reading 11.56V right at the battery and at the wire on the alternator.

Attached is a schematic of the charging circuit. Ensure you have battery voltage at the Red wire when ignition switch is turned on.

The main mast should have battery voltage with engine not running and charging voltage with engine running.

If you are not able to get the correct charging, the alternator is faulty. A bench test sometimes do not work.

Will a alternator not sending the right charging voltage cause the fans to not turn on.

If there is insufficient voltage, the fan might not work. Even if it works, the turning speed would be low. Test the fan motor terminals for battery voltage.

you could have a fault in the wiring circuit causing the non-charging and fans not turning on.


Do you have battery voltage at the Red wire?

The voltage reading I am getting at the mast is the same as battery voltage of 12.06V and the red wire is .001V with Key on engine off and .005V with engine on. What is the voltage reading supposed to be?

Unplug the RED wire and test the voltage again. If you have battery voltage, replace the alternator. If you do not have battery voltage, check if the charge indicator light in meter cluster comes on. If it does not come on, check Fuse 1D in underash fuse box.

Voltage is controlled by the PCM and you could have a faulty PCM. Trace the Red wire to the PCM and test the terminals for battery voltage. If voltage is not available, and meter cluster light comes on, you have a bad PCM.

The voltage reading unplugged at red wire is .017V with Engine off and .023V with engine running. Are nthe readings about what it should be?

What should the voltage reading be? Should it be a small amount of volts or should it be closer to 12V.

voltage at the pin is 9.47V however the voltage at the red wire to the connecting PCM terminal is .017V. Should that happen, should there be over a (V drop when the wire harness is connected to the PCM?

The meter cluster comes on.

You have a break between the PCM and Red wire to alternator.

Some where at the wire harness I would assume. I have 9.47V when disconnected and .017 when the harness is connected. I am assuming then the connecting pin and the red wire or not fully connecting then?

Do you mean you have 9.47 V at alternator Red wire with ignition turned on when disconnected?

I have been checking the red wire that comes from the PCM. When the wire harness at the PCM is disconnected the voltage is 9.47V with KOEO, when the wire harness is connected the red wire from the PCM is .017V.

Ok, that means the wire is good.

In this case either you have a bad PCM or alternator.

What should the voltage at the red wire be when the Key is on and engine off?

Is there a way to determine which one is going to be bad? The alternator reading the the red wire connected at alternator with koeoff is .005V and with the red wire disconnected at the alternator the reading is .017V. Is this normal.

If mt ECM/PCM is bad is there a way I can check to see if there is a wire that could be shorting out the ECM. This would be the third one in 3 years.

do you know which pin connection from the pcm the alternator connects too as well as the on from the relays for the cooling fan.

Do you have a wiring diagram for the PCM

Lets us atart all over with basic testing of the alternator.

Disconnect the Red wire from alternator and turn ignition switch on. Charge indicator should come on.

With Red wire disconnected, the RED wire should have battery voltage when ignition switch is turned on.

Red wire is connected to PCM terminal B4.

When the red wire is disconnected from alternator the voltage reading is .017V. By charge indicator I assume it is the on the dash showing approximate voltage of battery, if so it comes on.

Is your dash equipped with gauge or charge indicator light?