windows go down no key no command..

[j cAT]

This is a 2005 nissan max. 3.5l sedan...with the key hung up in the house after a period of time the windows front 2 only will drop 1/2 way then after another period of time drop all the way....have removed battery to stop but on reconnecting it starts all over again.....

[Nahkapohjola]

Originally Posted by j cAT

...with the key hung up in the house after a period of time ...

...hung up the key in the house after a period of time the 1/2 windows front only will drop 2 way.

[j cAT]

Originally Posted by Nahkapohjola

...hung up the key in the house after a period of time the 1/2 windows front only will drop 2 way.

with 12v applied to the window regulators at all times this is a serious design flaw....unless you live in a perfect vehicle climate...

I still can't understand how the 2 front windows drop by themselves exactly the same amount....

If one window did this, then is is explainable. as the pcb controling board is most likely defective or contaminated...

on a 2005 where is this pcb located????

[Nahkapohjola]

Originally Posted by j cAT

with 12v applied to the window regulators at all times this ...

+12V is applied only on demand, ctrl via data bus (havin +5V signal level = asthmatic for excess moisture). That statement is based on my belief that the Maxima door ctrl system databus -design has been unchanged last 10 yrs. Anyways the answer for your location q can be found via links here http://www.cardomain.com/ride/748507/13

If moisture can be seen as a suspect, dry out doors and relevant harness connectors, add contact grease.

[j cAT]

Originally Posted by Nahkapohjola

+12V is applied only on demand, ctrl via data bus (havin +5V signal level = asthmatic for excess moisture). That statement is based on my belief that the Maxima door ctrl system databus -design has been unchanged last 10 yrs. Anyways the answer for your location q can be found via links here http://www.cardomain.com/ride/748507/13

If moisture can be seen as a suspect, dry out doors and relevant harness connectors, add contact grease.

It appears that the door window pcb is in the door of its control.also the pcb always has 12volts to it....if a leakage of current occurs of a few MA. this could account for these windows operating as if the key commanded the windows to drop...

the doors look dry but, I guess I'll have to remove the door panels and clean the pcb with cleaner if dirty....and check the door lock switch also..

today it appears not to be doing this...but it did not rain today...


thanks for your direction......

[Nahkapohjola]

Originally Posted by j cAT

...also the pcb always has 12volts to it.........

Yes, true, the drivers door ctrl pcb has always +12v, other doors and their win motors will get the supply on demand.

Normally moisture isnt a problem. Maybe a seal is badly seated, broken, and/or pcb lacquer is not adequate? Minuscle moist on processor pins can have such weird response.

I'd start by opening the drivers door sw box. If no visible problems, switches ok and +12V is measured to be healthy, then I'd check all wirings to front doors, find a new pcb. I quess rear doors & wiring problems are out of question as weak data bus signal paralyzes first the rear doors (=long wiring 'eats' signal level).