I've got a few questions about this. First off, what is the likelyhood of the cruise control module going bad? Also, I see on the O'Reilly auto website that they have a cc fuse, but I don't see a listing for one on the fuse block. Where would it be? I have an '84 Z28. I'm trying to trace down this problem, and have it narrowed down to this or the harness (i think). Any help would be appreciated. Thanks

Also, if I am not getting any power to the cc module, would the problem then be in the turn signal lever?

 

Ok. here is some more info. I've tested the switch at the brake pedal, and i'm getting ~4.8 volts under 35 mph, and ~12.8 volts over 35. I'm also not getting any vacuum through the hose that connects to the switch. I've also checked to see if I'm getting power to the cruise control module, and I am, through terminal A (~12.8 volts). The question that I have now is that how do I test to see if there is voltage at the servo? Also, is there a way to test the module?

By the way, I've figured out where the fuse is.

 

These are the steps for checking voltage at the CC module for a 1986 cruise control. I'm not sure if it is the same for an 84 but it may help.

 

the rest of the steps:

 

Thanks BigTiggBoy, that helped tremendously. I've done all the tests that I can from that list, and the only thing that failed was the one with the cruise on and the set switch pressed. I'm not getting any voltage at the terminals L & J. So what I did was looked at the connector where that turn signal lever plugs into, (with it still plugged in) I tested the green wire to ground for voltage, and got 12 volts with cruise on, and 0 volts with it off. I then tested the red wire, the one that when you press the set switch, it registers, and I got 12 volts there when it was pressed. So the only thing that I can think of was that there might be a relay or an inline fuse or something else that I'm missing for this to not work. Anybody else have any ideas?

 

According to the 86 repair manual, your next step is to disconnect C223 and check continuity between terminals B and D of the male half with the Set switch pressed.
If the switch is open, replace the Multi Function lever.

Step 2: Check for an open in the DK BLUE wire(84) between terminal D of connector C223 and terminal L of the module.

By the way, C223 has 4 cavities and is located behind LH side of I/P, at the base of the steering column.