SVT CL/AV Fan Connection -- Help!

Hoping I can get some quick info from you fine folks. Here is my story:

I unscrewed the upper chassis of my SVT AV (same as CL for these purposes) to get at the preamp tubes. When I pulled the chassis out, the front grille came off.

As it came off, it pulled loose the wires that connect the fan. There are two wires coming out of the lower chassis to connect to the fan, but seemingly only one wire coming out of the fan itself.

Is one of the two wires coming out of the chassis the ground? How do I know which wire connects to the fan?

I've included a couple of pics that illustrate my issue. Thanks in advance for any help!

 

Thanks very much, Hodgy. That's what I ended up doing.