Help: Mark IV reverb problems (troubleshooting)

[Rydock]

So ever since I had the Mark IV, I've never had a single chance to hear the reverb. I built a headshell for my amp a few months ago, and didn't bother installing the reverb. Now, I want to give it a try to hear how it sounds, for curiosity's sake. I'm pretty sure I've hooked it up correctly: Thick gray wire, near the front on the amp; thin white behind it; gray to input of the tank; white to the output. I tried playing with the reverb set really high, and I don't hear any reverb coming through. When I shake the reverb tank, you can hear the typical "crash" sound coming through the speakers. It seems the gray wire has single flowing through it, but I don't know what's wrong with the white wire. Any help would be appreciated.

 

[Rydock]

please...anybody help me.

 

[dodger916]

My Mark IV has the same connections at the chassis, but the white wire is connected to input (left side of tank when viewed from rear).