Hello I just registered to this forum, I have a Pacifica AWD 3.5L of 2004.
Unfortunately I have some issues with it at the moment and I was hoping to find somebody who could guide me or any give me any helpful tips.

Here is the thing, the coolant is overheating and even boiling that it drained it. There is no leak under the car, however while figuring out whats wrong with it, I test drove it around the block (coolant filled up of course), then I parked and checked if the fans were working, well they were not, and the water started going up pretty high as I parked. So I am suggesting there's something wrong with the fans right ?
My first question is: Is it because the front fans (both) are not working that my engine (well coolant) is overheating ?
Second Question: How can I test the different parts of the fan assembly, wiring, relays to find out where the problem is coming from ? I checked the fuses under the hood and the ones related to the fans seems in good shape.

Please let me know if you guys have any tips on that problem, I would really appreciate, thanks for your time.

Mathias.

 

If you run the air conditioner the fans should turn on to cool the condenser. if not you need to start at the fans and work back untill you find the problem. unplug the fans and appl 12 volts and see if they run. then see if the relay's are working(swap out another relay and see if it works see if the relay's are getting 12 volts to turn them on. the engine temp sensor tells the computer the temp of the coolant and the the computer turns on the fans. you should b able to drive above 35 mph and not have an over heating problem because there is enough air passing through the radiator to cool properly. if you still have a over heat problem look at the thermostat. do all of this and re post the results. ill be checking back.

 

Turn on the ac see if the fans come on then

 

Thank you for your reply, I already tested both fans by wiring it directly to the battery, they are both working. I also tried by seeing if they work on low speed by turning the A/C on, they are not working with A/C on, so I think from what you told me, I have go along the wiring and test the relays with a voltmeter and see if it is coming from there.

I will be reposting once I tested the relays. Thank you again !!

 

relays are not going to be an issue not the kinda relay u can test that is
T have a Solid state relay under the bumper fascia it controls the fans that is what U will more then likely need to replace

 

I actually switched some relays in the fuse box that I saw missing which I didn't catch in the first place, I actually followed your advice in switching the relays thanks and when turning on the A/C the fans were now working !! I test drove the car, the water temperature gauge was right below the middle and stayed there for the whole time. So far the issue seems to be resolved the fans are working now !
Thank you guys for the replies, I really appreciate your help and hope this thread will help others in the same situation.

I will be checking this forum for more info!!

Have a Great Night !!

 

Well then i guess you found the problem. just replace the bad one. I have NEVER herd of a relay under the bumper and i have been a mechanic sense 1969. when ever you have a problem like this you start at what doesn't work and work backwards.

Good luck

Charles c.

 

Its a solid state pulse with modulated relay nothing inside moves. It on the bumper to get direst air flow and keep it cool They are quite common in Mini vans from 96-2004 and Pac and among other newer cars.

 

Kevin.

While i am reading your post i don't speak dutch. i don't fully understand what your trying to say.

 

OPERATION
The solid state radiator fan relay is controlled by the Powertrain Control Module (PCM) by way of a Pulse Width Modulated (PWM) signal. The relay control circuit supplies a 12 volt signal to the PCM. The PCM then pulses the ground circuit to achieve fan on time. The relay provides a voltage to the fan motors which is proportional to the pulse width it receives from the PCM. The duty cycle ranges from 30% for low speed operation, then ramps-up to 100% for high speed operation. This fan control system provides infinitely variable fan speeds, allowing for improved fan noise, A/C performance, better engine cooling, and additional vehicle power.

To control operation of the relay, the PCM looks at inputs from:

Engine coolant temperature
A/C pressure transducer
Ambient temperature from the body controller
Vehicle speed
Transmission oil temperature