at power supply for fridge 12dc

Hi, I have a 12VDC fridge and am trying to convert a computer power box to supply power to it. I started with a ATX type and have problems with it resetting itself after the compressor restarts itself after reaching temp. I have a 10Watt resistor connected to the 5V wiring to keep it running during full temp switch off, but when frigde restarts itself the power supply resets. I am now trying a AT 230W box and it does not reset but under load I only get 10.4v, not enough to operate fridge for cooling. Any sugestions how to lift voltage as when connected to motherboard and 4 hdd's it generates 12v. Thanks Tim

Sorry I should add that the fridge is 12v 4.2amp and the power box is 12v 8amp. I have tied 2 x AT type boxes with same result. Thanks Tim

The current required to start the compressor is way more than the 4.2 amps required to keep it running.  You need a bigger power supply.  Do you have an ATX supply laying around?

Hi, I have several power supplys, AT and ATX, problem with the ATX is it trips when the fridge turns back on after reching temp. The AT does not but only produces under 12v, it is the biggest AT type I can find at 230w. Thanks Tim

How are you turning on the ATX supply?

I have soldered the green and grey (the m/board switch wires) wire together, so it is always on

I am not familiar with the grey wire.  I do know that if you ground the green wire it will stay on.   But if yoiu know that green to grey will keep it on.  So you are saying that it stays on until the compressor cuts off then it resets?

hi again, the grey green is the switch, this is not the problem I am having, the ATX with the grey - green is a modern protecting power supply, it protects itself from destruction by resetting itself, the load from start up after is over what it expects so cut off. The AT does not have this function but I can not get it to delliver true 12v. I nkow my wording may not be fully correct, but the first post say's more. Tim