12v power loss?

[omega maximus]

I’m trying to run my accessories off a separate 12v source, my problem is whenever I turn my cold cathodes on the fan slows down, how do I maintain the 12v I need without degrading power loss. Thanks.

[Aguiluz]

It seems like the peltier draws a hell of a lot of power that whatever your seperate 12V source is, it's not keeping up with the load. (Not enough amperage.) It can also be caused by wires that are too thin.