Cooling fans
97pontiacgrl
05-24-2010, 03:30 PM
Does anyone know how to test the engine cooling fan motors? If so, do I need a special tool or attachment for my multimeter?
rkvons
06-14-2010, 12:30 PM
Does anyone know how to test the engine cooling fan motors? If so, do I need a special tool or attachment for my multimeter?
There should be two wires that go to your fan motor. Attach your Digital Volt Meter (DVM) to them and see what's on them. When 12V appears across them, they should be on. If not, they are bad. If there is never 12V on them, something else is wrong.
There should be two wires that go to your fan motor. Attach your Digital Volt Meter (DVM) to them and see what's on them. When 12V appears across them, they should be on. If not, they are bad. If there is never 12V on them, something else is wrong.
jarl
06-15-2010, 10:12 AM
Close, but no cigar...
Making sure the fans will not come on (switch in the "off" position, cool engine, battery disconnected and whatnot), disconnect the cables going to the fan. Use your digital multimeter on the "Ohm" scale, and measure the resistivity between the two fan motor terminals. If it's close to 0 or infinity ("high" or something like that displayed) the fan motor is gone. My guess is that for these motors a normal reading will be a few ohms.
Alternatively, you can just do something similar to what rkvons suggests, but providing the 12v yourself: disconnect the cables going to one motor, attach to the motor's side terminals two thick cables long enough to get to the battery (or to a battery) and connect the cables to the battery. Adding a fuse somewhere would be a nice detail in case something is seriously wrong.
Your best bet is making sure the fuses are Ok. What makes you believe the fans are bad?
More importantly: what car are we talking about?
Making sure the fans will not come on (switch in the "off" position, cool engine, battery disconnected and whatnot), disconnect the cables going to the fan. Use your digital multimeter on the "Ohm" scale, and measure the resistivity between the two fan motor terminals. If it's close to 0 or infinity ("high" or something like that displayed) the fan motor is gone. My guess is that for these motors a normal reading will be a few ohms.
Alternatively, you can just do something similar to what rkvons suggests, but providing the 12v yourself: disconnect the cables going to one motor, attach to the motor's side terminals two thick cables long enough to get to the battery (or to a battery) and connect the cables to the battery. Adding a fuse somewhere would be a nice detail in case something is seriously wrong.
Your best bet is making sure the fuses are Ok. What makes you believe the fans are bad?
More importantly: what car are we talking about?
ricebike
06-15-2010, 12:40 PM
fastest and easiest way to see if the fan motors turn on
while running, turn your AC on full blast & the electrical fan(s) should go on
while running, turn your AC on full blast & the electrical fan(s) should go on
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