Acer vm670g fan speed is too high How to change fan speed why is it running so fats

Both radiator cooling fans are running all the time ? Key off ? The cooling fan opperation
HOW they work
Cooling Fan Control
The engine cooling fan system consists of 2 cooling fans and 3 relays. The relays are powered by the battery positive voltage circuit and controlled by a switched ground from the powertrain control module (PCM).
During low speed operation, the PCM supplies the ground path for the low speed cooling fan relay through the low speed cooling fan relay control circuit. This energizes the cooling fan low relay coil, closes the relay contacts, and supplies battery positive voltage from the COOL FAN LO fuse through the cooling fan motor supply voltage circuit to the cooling fan. During high speed operation the PCM supplies the ground path for the cooling fan low relay through the low speed cooling fan relay control circuit. After a 3-second delay, the PCM supplies a ground path for the cooling fan high relay and the s/p cooling fan relay through the high speed fan relay control circuit.
The PCM commands the fan on under the following conditions:
• Engine coolant temperature exceeds approximately 98°C (208°F) Low Fan Speed
• Engine coolant temperature exceeds approximately 102°C (216°F) High Fan Speed
• A/C refrigerant pressure exceeds 361 kPa (52 psi) Low Fan Speed
• A/C refrigerant pressure exceeds 2100 kPa (300 psi) High Fan Speed
• When the engine coolant temperature exceeds 112°C (234°F) at key off, the fan high speed will run for up to 300 seconds. If within that time frame 102°C (216°F) is reached then fan speed will change from high to low speed. If within that time frame 99°C (210°F) is reached then fan speed will change from low to off.
The PCM commands the fan off under the following conditions:
• A/C is requested and engine speed exceeds 6,240 RPM
• Engine coolant temperature exceeds approximately 99°C (210°F) turns the cooling fans from low to off.

sounds like one of the relays are stuck closed .

Cooling Fan Always On
Step
Action
Yes
No
Schematic Reference: Engine Cooling Schematics , HVAC Schematics in HVAC Systems - Manual
Connector End View Reference: Cooling System Connector End Views
DEFINITION: One or both engine cooling fan motors run continuously in high or low speed.
1
Did you perform the Diagnostic System Check - Vehicle?
Go to Step 2
Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2
Install a scan tool.
Turn ON the ignition, with the engine OFF.
With a scan tool, command the Fans Low Speed ON and OFF.
Are one or both cooling fans ON?
Go to Step 3
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3
Are both cooling fans running continuously?
Go to Step 4
Go to Step 6
4
Are both cooling fans running continuously in high speed?
Go to Step 5
Go to Step 7
5
Test the low reference circuit of the A/C refrigerant pressure sensor for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 18
Go to Step 14
6
Important: The S/P relay is located under the front bumper on the drivers side of the vehicle.
Remove the cool fan S/P relay.
Did the right cooling fan turn OFF?
Go to Step 10
Go to Step 8
7
Remove the cool fan LOW relay.
Did the cooling fans turn OFF?

You are talking about your blower fan for the air conditioner and heater right? More information will be needed to solve the problem.

When you say it barely changes speeds, does that mean it doesnt speed up, or doesnt slow down? By that I mean, is it "stuck" on low, or high?

Most blower fans run at different speeds through the use of a multi-stage resistor built into the fan switch circuit. Low speed is a high value resistor, medium speed is a low value one, and high speed is the fan running without any resistance.

If your fan is running on high and doesnt seem to want to run on lower speeds, the resistor pack may be failing. If the fan is running on low speed only, it may be that the fan itself is beginning to fail, or that the lubricant in it has gotten gummy.

you need to go into the bios settings to change how the fans operate.

Have you tried changing the fan relays? Sounds like they may be stuck on.

there is a starter solenoid inside it works the speed setting. controls speed 1-2-3. 4 it bypasses it. in side the fan you will see a black box with c66 somthing that will need to be changed as that is the part that controls the speed.

Helllo you have maybe flashed the bios with a wrong one.

The acer homepage is here:

http://support.acer.com/product/default.aspx?modelId=481

ALWAYS download bios upgrade at the computers homepage !!!!

You need to contact the acer support in your country
they can help you with that.

Good luck

i have acer power fv desktop win 7 1gb ram ,CPU fan running high speed

Most fans have a small rectangular multi-tap capacitor connected to the speed control in the fan. It is likely that this has gone partially bad. The capacitance values are printed on it. Lighting stores and big box hardware stores generally carry replacements.

plug out the power cable connected in your CPU and replug it again still its not working you need to change the power cable

Compressors on these units runs at only one speed. The change to high cool is only a change in blower speed moving air faster over the cooling coil. I would have the running capacitor for the fan motor checked. A bad capacitor can cause your type of problem. The other problem could be that the high speed winding in the fan motor is bad. Try it operation in the fan only position through the two speeds. If it works in the low and high speed for fan only your problem could be in the selector switch.