how do test the radiator fan motor???

[Red Baron]

I have used the search, but the information that I have found did not really help me, sooo....I want to test my radiator fan motor to make sure that both the low and high speeds are working...how do i do this? On this picture, wire 1 is blue/purple, #2 is brown w/yellow stripe, and #3 is black(?)...which one is for the low speed and which one is for the high speed?

When the temp. is low enough that the fans don't turn on, there should be no current at the pins at this plug, correct? (The wiring from this plug goes to some other wiring, the plug that connects to this plug goes to the fan motor) I am trying to determine if either my fan motor or relay have gone bad. If it's the motor, then i will just replace it, if it's the relay, i want to bypass it by putting a switch inside the car to operate it manually. Any help is greatly appreciated hail cuz i have tomorrow eek! to work on my car. Thanx. thumb

 

[autobahnsho]

I believe when you run the codes (see www.shotimes.com under maintenance) it tests the fan and will give you a code if it's not working right.

good luck!

 

[Red Baron]

Well, I have tested the plug and I let the temp rise to above the "N" and the wire that is for the high speed recieved current, so I connected the plugs together and the fan turned on, on high and then went to low. So, now I know that the motor and the relay are both working.

Now, when I run the A/C, is the fan motor supposed to run on high? or low? because it is running on low. Would the ECT sensor cause the fan to turn on later and at a higher temp than it would normally kick in at, and also for a shorter time? Thanks for the help!

 

[autobahnsho]

I know the fan is supposed to run as needed, not all the time. But I can't help you past this. Sorry. shrug

 

[SHOZ123]

The cooling fan system is controlled during vehicle operation by the Constant Control Relay Module (CCRM) and Powertrain Control Module (PCM) 12A650 which will energize the radiator electric motor under the following conditions:

l. Radiator electric motor is turned on with reduced current for the 3.0L SHO and on at low speed for 3.0L, 3.2L SHO and 3.8L if:

a. Engine temperature is higher than normal. Radiator electric motor starts running at 102°C (215°F) and stops running at 99°C (210°F).

b. A/C clutch is engaged.

l. Cooling fan will run at high speed if:

a. Engine temperature is higher than desirable and radiator electric motor has been operating at low speed. Radiator electric motor starts running at high speed at 110°C (230°F) and stops running at 107°C (224°F).

On 3.2L SHO engines, low speed radiator electric motor operation is achieved by using a dropping resistor in series with the motors.

The 3.0L/3.0L FF, 3.0L SHO and 3.8L use a dual winding radiator electric motor in which low speed fan control is achieved through the low fan control winding circuit (no dropping resistor).

The normal operation and cycling of the radiator electric motor causes the temperature gauge indicator to read between the mid-point and upper portion of the temperature gauge scale.

l. The slightly higher indicator reading returns to mid-point when radiator electric motor operation begins.

 

[Red Baron]

Ok...that verifies that my fan and relay are working the way they are suppose to...

I changed out my ECT sensor and the car seems to run better,maybe my imagination....my mileage was about 215 miles before the low fuel light turned on before I changed out the ECT...we'll see if it improves with the ECT exchange....one reason I changed my ECT was that my exhaust tips looked a little too sooty (read that a faulty ECT could cause it to run rich, causing the sooty stuff), the radiator fan kicked on later than normal, as indicated on the gauge (in my opinion), and only stayed on for about 20 seconds...

But now, the fan still only kicks on at the O and stays on for 20 seconds or less, but the car seems to run and accelerate better...by changing out the ECT??? shrug Would the fan only staying on for 20 seconds be normal? Does it need to run longer? Is my fan motor drawing too much current, therefore, causing it to shut down early? squint Keep in mind that it does turn on when the A/C is on thumb ...I have verified that the low and high speeds work, and obviously the relay is working thumb ...I have a new ECT, temp. sending unit, radiator, thermostat, upper and lower hoses, and absolutely no coolant leaks ....my only thought is that it is the fan motor not running long enough when the relay sends the signal to turn on...on at the "O" and off slightly above the "R"...any opinions, thoughts, experiences? I await your responses pcorn Thanx for the help. beer

 

[AutoSHO]

Have you replaced the temp sender for the gauge in the dash?

It is not a very precision unit anyways, but it sounds like yours is on the hot side. In my car, as well as my friends' cars, the fan kicks or between the O-R and off at the top or middle of the M.

 

[Red Baron]

Yup...I replaced it just last week. Still acts the same....

 

[SHOZ123]

Sounds to me like you don't have a problem. The system is working just as it is designed.

 

[autobahnsho]

Ditto ShoZ123.

ps- 215miles/on one tank of gas?? You must really lead-foot. I do a mix of city, highway driving, like to get the secondaries open and hit the hp peak (around 6200rpms) and refill at 230-250miles. I never let the light come on.

 

[AutoSHO]

I second that. If I get under 300 miles before the light (comes on at 3-4 gallons left) I am worried. And I do not typically drive slow.

 

[Red Baron]

I'll see how many miles i get to my tank now that i changed out the ECT...one thing i noticed since i changed it out is that my exhaust tips are no longer sooty....

 

[SHOZ123]

one thing i noticed since i changed it out is that my exhaust tips are no longer sooty....

Every car I have ever owned have had sooty tips. That comes from frequent WOT usage.

 

[Red Baron]

Before I changed out the ECT, the tips of the tips would get very sooty quickly and i would clean them on a daily basis...but now i have yet to clean them since the sensor change...coincidence? shrug Don't know, but hey, it's