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Discussion Starter #1
My power window failed int my 98 Altima. I pulled the door trim and checked voltage at the harness going to the motor. I would get 12 volts to the motor, but I wasn't getting anyting to happen. I ohmed out the wires and didn't get any resistance in the motor winding, so I have come to the conclusion that the motor is bad or the internal motor fuse link is open. Am I correct in my diagnosis? If so, can I just buy the motor, or do I have to buy a regulator/motor combo? Also, how do I lower the window down low enough to get access to the retaining bolts to the window?
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Biru O' Kudasai
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I don't know if you have found the problem but from the symptoms the motor and regulator are not the problem the voltage should be there but the motor gets a data input from the power window switch. I think that is where I would start looking.

Troy
 

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Discussion Starter #3
I haven't actually fixed the problem yet, but I already ordered a regulator/motor combo. What do you mean by the the motor gets a data signal from the power window switch? When I was testing the motor, I would get 12 volts at the harness if I pressed the switch one way and it would reverse polarity if pressed the other way. It seems straight foward. Am I missing something? What kind of data signal are you refering to?


KA24Tech said:
I don't know if you have found the problem but from the symptoms the motor and regulator are not the problem the voltage should be there but the motor gets a data input from the power window switch. I think that is where I would start looking.

Troy
 

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Biru O' Kudasai
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I was using the 97 U13 Altima wiring diagram for diagnosing since I didn't have a 98 and as I found out today it is different than the your 98 L30 Altima.
The switch does reverse polarity to raise or lower the window as you have stated. To isolate the swich or the motor as the problem you should test the motor connection for continuity to ensure the breaker and motor have a current path. If it shows an open circuit see if the circuit breaker can be reset on the motor. Once the circuit is known good then run a power and ground to the motor from the battery if possible to check it's operation. If the motor doesn't operate then you have found the problem. If the motor tests good then the switch should be either swapped to test a known good switch, the old swiitch diassembled, cleaned and tested, or just replaced. I am sure that the switch is allowing the voltage you are reading thru but I am wondering if it is enough current to operate the window. Most of the time the contacts in the switch become burnt enough that a large amount of resistance stops the window from operating.

Troy
 

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Discussion Starter #5
Yeah, I was thinking about the voltage drop also when power was applied to the motor, but since the moto has no resistance, I'm thinking the motor breaker is open or the windings are shorted open. I didn't know that I could reset the motor breaker. I thought it was an internal breaker. I'll check it out though. As for how to lower the window when it is inoperable, do you know of a way to do it? I can't get to the retaining bolts that hold the glass to the regulator assemblly.



KA24Tech said:
I was using the 97 U13 Altima wiring diagram for diagnosing since I didn't have a 98 and as I found out today it is different than the your 98 L30 Altima.
The switch does reverse polarity to raise or lower the window as you have stated. To isolate the swich or the motor as the problem you should test the motor connection for continuity to ensure the breaker and motor have a current path. If it shows an open circuit see if the circuit breaker can be reset on the motor. Once the circuit is known good then run a power and ground to the motor from the battery if possible to check it's operation. If the motor doesn't operate then you have found the problem. If the motor tests good then the switch should be either swapped to test a known good switch, the old swiitch diassembled, cleaned and tested, or just replaced. I am sure that the switch is allowing the voltage you are reading thru but I am wondering if it is enough current to operate the window. Most of the time the contacts in the switch become burnt enough that a large amount of resistance stops the window from operating.

Troy
 
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