Hi, pgilliam1.
I was under the impression that NSX Prime was going through major restructuring as I couldn’t see the usual forum in my mobile phone until I scroll down a bit to reach the ‘First Generation NSX’ area.
Any way, it is unusual for both windows to suddenly stop working and sounded like you have loose connection at the driver door window switch module or faulty integrated control unit (please note that this is different from the power window control unit) but the answer to following questions and checks would help us in supporting you.
I'm afraid at this stage, you can ignore the power window (p/w) control unit especially if you can’t operate the passenger window.
Although I'm based in UK which is mainly RHD NSX, I'm using the word 'driver' and 'passenger' as if I'm drivng the LHD model.
Please do not confuse the integrated control unit with the p/w control unit. They are two different things.
The integrated control unit is located at the fuse panel at the driver foot area.
The p/w control unit is located at the door panel behind the door card.
1. Passenger window sw
Can you operate the passenger window using the switch located at the passenger door while the ‘MAIN’ sw located on the driver door in 'ON' position?
As you mentioned, the p/w control unit only affects the driver window and not the passenger one.
Also, the power line to the passenger window switch located at the passenger door is spliced before reaching the driver side so it has its own power line and the only thing shared between the two sides is the GND circuit through the ‘MAIN’ and Pass switches located on the driver switch module.
So, if you can’t operate the passenger window using the switch located on the passenger door panel, then the chances are;
you don’t have the +12V (fuse, p/w relay or integrated control unit)
you don’t have the GND circuit (bad connection under the driver window switch, faulty passenger and/or driver window switch)
or your passenger window regulator motor is faulty.
If you removed your door card, you can easily check the motor by applying the power to it but for the time being, not required.
2. Power line
When you carried out the input test on the p/w control unit, did you see +12V at the White/Yellow wire on the 6pin connector?
This is important to confirm that your p/w relay and the integrated control unit are operating fine.
If you didn’t check this, you can do so if your driver side door card is still off or you can simply go to the pentagonal main relay box under the bonnet and check the voltage at the two 20A fuses for each window.
When your IG key is in ‘On’ position, you should see 12V at these two fuses.
If not, you have problem with the p/w relay, integrated control unit or the fuse.
3. Driver side switch module
If you have basic electronics knowledge and workshop manual, then you will understand how the passenger side window operates using the driver switch module.
With the circuit diagram on the manual, you can check the power line and also the GND circuit for the passenger window.
For example, you should see 12V at the Blue/Black and White/Yellow cables at the driver door switch module when the IG key is in ‘ON’ position.
Black cable should be always at the GND level and without operating the switch, you should see GND level at the Blue/Green and Blue/Yellow cables.
If not, you have broken GND circuit somewhere between the driver and passenger window circuits.
Also, please check the condition of the each female and male terminals inside the connector at the switch module as well as on the wiring side.
On some of the NSX, I noticed broken contact plate inside the female terminal especially on the door lock/unlock switch.
I have seen the integrated control module to fail resulting in no rear defogger operation but everything else were operating fine.
Very rare case but it is one of the possibility because if it fails, it won't switch on the p/w relay resulting in no power to both windows.
I think this is enough to start with.
Kaz
(FULL EU model 1991)
