Test Connection Unplugged!
 

So, I wanted to check the duty cycle of the frequency valve. It turns out, the connection is not. The ground wire isn't connected to anything, nor is the red wire. They are just hanging out. I assume I can just ground it anywhere, but where is the red wire supposed to emanate from? The schematic shows I-21, but that doesn't mean anything to me. Thanks.

Okay, I looked in the Bentley's, and it refers to Fuse #22. Is this Fuse #1 in the engine compartment? The same one as the rear window defogger/wiper?

The frequency valve is on the same fuse as the clock and the interior/ceiling light.

I'm going to revive this post because I am asking a similar question in another one.

Basically, where does the power to the test connection go?

My diagram shows "I 21" as well. Is what tcar is saying that "I 21" corresponds to the clock/interior light fuse?