4 Pin Molex Connector With Only 3 Wires

[Amadeus Kota]

I have this Molex power connector for a fan and they usually have 4 wires. After a quick research I understand there's a yellow and red wire for 5V and 12V, then 2 black wires for grounds. The one I have has only 1 ground and I'm wondering whether that's a problem. It's currently connected to a fan with 4 wires. I can't seem to find an answer to this, so would anyone here be able to help? Greatly appreciated!

 

[Automata]

Can you take a picture of what you mean? A fan connected to a molex connector should only require 2 wires.

 

[ATMINSIDE]

If the fan has four wires, it most likely has PWM capability.
Why not plug this in where you can control the speed instead of running it at full tilt?

 

[trents]

Actually, you only need two wires: one for power and one for the ground. If the colored wire is red and the position sequence of the red wire has not been changed (i.e., if it is the same place as the red wire of the lead coming from the PSU) then the fan will be getting 5v. This is a common way of slowing down a loud fan to make it quieter. Works fine if the fan has a low enough impedence so as no to stall out. If the colored wire is yellow then he fan will be getting a full 12v.

 

[Amadeus Kota]

Apologies for the late reply. A lot of things came up and I was unable to return to this for a number of days.
Here's the photo of the connector. As seen in the picture, from right to left there is a yellow wire (12V?), a black wire (ground?), a red one (5V?), and the last slot is empty. I find this layout strange. Isn't the red wire where a ground would normally be found?
The fan has 4 wires, but it's just on the side panel and I don't have a fan speed controller, so fan speed control doesn't really matter here as long as it's generating enough airflow.

 

[Blaylock]

Something is fishy there. Can you post a pic of where that white molex connects or runs to the fan? The red (5v) line is connected to ground.

 

[jaymz9350]

If the 5v line is connected where the ground should be that will make the fan run at 7v.

 

[Blaylock]

I'm pretty sure you skip the ground and ground the fan to the 5v line.

Edit: like this


Re-Edit: This looks useful

 

[jaymz9350]

You're right, I got the way the wires are in the pic mixed up