Wanted to take a PSU and elimanate the 20 pin harness and setup a power switch
on a case. All I want is 2 of the molex 4 pin harness to run fans, lights and a 6 channel dual voltage baybus (fan controller 7Volt & 12Volt)

Could I just open the power supply up and remove all the wire for the 20 pin harness except for the 2 wires I need for a external power switch?

It really depends on the PSU.

On the ATX PSU the switch is just a momentary switch and not one that is always on.

What PSU are we talking here?

Tmod

Or, you could just get a Meanwell PSU. Or, buy a cheap modular (those Ultras are being shown for like $20 now) since I expect you'll be using it for just some cooling/accessories?

What I'm thinking of doing is taking a gutted compaq presario case I have and installing to heater cores that are about 9" x9" x2' along both sides of the case and then in the front and rear of the case installing 4 to 6 panaflo 120mm fans
the fans will pull air out of the case in otherwords the air from outside will be pulled in through the rads and exhausted out the front and back. it would have a 350GPH + pump in the case and a 6 channel dual voltage baybus to control fans 7V & 12V speed and Quick connect connections for water lines on the back of the case Thats what I need a PSU for to power pump fans and lights.

What do you think of my external H20 cooling box?

catkicker,

You can cut everything except one black and the green wire.

#14 is the green and #15 should be a black wire.

Now hook a switch up to those two and it will power up when the switch is on.

This is assuming a ATX psu with 20 pin connector.

BE CAREFUL WHEN GOING INTO A PSU UNIT AS THE CAPACITORS WILL HOLD POWER FOR QUITE SOME TIME.

Tmod

I can vouch for that..lol..

I did sense mods on a psu and touched one of the caps..

OUCH !! Is all I can say..:angel:

Before you open it jump the green and black wire to discharge the power left in it.. Even after doing that there might be some power left so be carefull..

Thank's for the warning ATX 350Watt PSU should work well for this. Fun project should be great for cooling and pretty quiet with the panaflo's and the pump I picked out.