I think my 12v adapter may be bad, but I am unsure of how to test it for sure. Will a wiggy work for testing a 12v power supply, or does it work only for a/c power? I have power to the adapter for sure, but my fan will not turn on once connected, and I get no signal when a wiggy is connected to the spliced wires of the 12v adapter. I am not sure if I am doing something wrong, but it would suck if that thing is bad, as I have already stripped the wires!!! Any help would be appreciated!

You could test the DC side with a flashlight bulb or a small car lamp(dome light/turn signal). The fan won't run if you swap the DC leads?

I have the PCAC fan, and it won't run no matter how I connect the leads. I have the red and black hooked up to the 12V adapter leads, and I have the yellow wires end wrapped with electrical tape. There isn't an onn/off switch on the fan is there? I have the fan speed turned all the way up.

I touched the 2 leads of the adapter to the base of a flashlight bulb and nothing happened. I know the bulb is good, so that is not the problem. I don't know what more there can be than stripping the two wires and connecting them where they go. Either I am making more of this than their is, or the adapter just plain old does not work.

Shouldn't the yellow wire be connected to the +12V? The yellow wires on a computer case power supply are +12V. Red is +5V and black is ground of course. What kind of power adapter do you have? Make sure it is DC not AC (VAC, etc.).

the yellow wire in this situation is a tach wire and not used.

THe underside of the adapter says AC adapter. 120vac in, 12v dc out. The 12v dc out should be what I want. It is what they gave me at radio shack when I asked. Not that they are always correct, but saying 12v dc out sounds correct.