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The 4 wire connection to the roof pump has a large black and red wire and a small black and purple wire. I have power to the large wires but not the small wires. Can anyone tell me if those small wires are supposed to have power or are they for some kind of signal. Thanks all. 馃槑
 

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The small wires are for the thermistor, used to sense pump temperature. The purple should read some voltage with a voltmeter. I am not sure if a 5 volt or 12 volt reference voltage. The only time you would read 5 or 12 would be with it unplugged. Other times it will be lower.
Do not use test light, use high impedance meter.
The polarity of the other two reverses as the pump motor reverses, like a window motor and should not have power unless button is depressed. Depending on up or down will vary if red is power with black serving as ground path or black is power and red serves as ground path in opposite direction.
 

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Discussion Starter #3
The small wires are for the thermistor, used to sense pump temperature. The purple should read some voltage with a voltmeter. I am not sure if a 5 volt or 12 volt reference voltage. The only time you would read 5 or 12 would be with it unplugged. Other times it will be lower.
Do not use test light, use high impedance meter.
The polarity of the other two reverses as the pump motor reverses, like a window motor and should not have power unless button is depressed. Depending on up or down will vary if red is power with black serving as ground path or black is power and red serves as ground path in opposite direction.
Thanks. Looks like I鈥檒l be sending my pump/motor to Top Hydraulics to be rebuilt. i have power all over but no pump. 鈽
 

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@Groceryman101 , You stated you had power to both large wires. Yet, you asked what small wires were for?
You did not ask how to test pump circuit.

The pump is not a common failure component.
I am not sure of your test procedures for power, as both wires can't be powered at same time and expect motor to work.
As a second test i recommend my students test power window motor circuits by connecting a 12 volt test light (or larger light) in place of the motor. The see if light comes on in both directions of the switch. If light does not illuminate as pump is commanded up and down problem is not in pump.
So i would suggest with connector to pump still plugged in, back probe into large wires with a 12 volt light. It should illuminate as switch is moved both up and down. If you are sure you have good connections and it does not light the problem is most likely NOT the pump. You cannot disconnect the connector to perform this test as the thermistor circuit would be open and this may prevent pump operation.
Its fairly easy to perform this additional test to be sure your diagnosis is correct.

EDIT
you could also backprobe with your voltmeter. Connect red lead to red wire and black lead to black wire. Observe meter as you command top up and down. If circuits sre good you should see 12 vdc in one direction and -12vdc the other direction, anything else suggests circuit problems not a pump problem.
 
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