1990 Nissan 300zx

Hey everyone.

I have a 1990 Nissan 300zx 2+2

The power windows in the car are extremely messed up. At one point after buying the car they drivers side window would go up and down, But the passenger side wouldn’t go down it would only go down. So i replaced the passenger side window motor and the regulator. That did work the window would move at all after that. I checked all the fuses got now switches and a new power window Amplifier and now either window will move up or down. Any help?

Do you have a service manual to help you diagnose the window problem?

No i don’t.

Without a manual you’re really just throwing parts at the car and hoping something will work. You have to test individual components to see what’s working and what isn’t. A manual is worth its weight in gold for things like this.

If your local book store or auto parts store doesn’t have a manual for your car, try Books4Cars.com.

They have a good selection of inexpensive used manuals. If you plan to keep this car I recommend purchasing a service manual. Factory books are best, but others, like Haynes, are helpful for less money.

Alright thanks a lot. I’ll try and run down a manual.
Any suggestions knowing that i don’t have the manual what the problem might be?

Yup, I suspect that you have wires in the 19 year old wiring harness that have chafed, shorted to ground, and possibly even broken in the area where the harness goes through the car’s chassis into the driver’s door where the switch console is located.

You’ll need a schematic, a bit of electrical knowledge, a manual as McP said, and a multimeter with pin probes. You may need to remove the outer insulation from the bundle, untie the bundle, and seperate the wires to probe them. A good worklight is a blessing also as you can much more readily see insulation breaks with good lighting.

Good luck.