These are the steps to install a cable and mast for a Delco Power unit that has a mechanical stop. These units were used by GM from 1990-2002, not all Delco units used a mechanical stop.  To know if you have this style, your unit will shut off on its own if the cable that moves the mast is broken or not installed, if it shuts off after about 8 seconds on its own then these are the instructions on installing a cable and mast.

1. Remove the power unit from the car, take it to your work bench. 

How to Remove the Mast:  A through E below.

A. Extent the mast and unscrew the tip from the solid rod section of the mast.

B. Drill off all the rivets that are used to hold the case together.  Then important, note with a magic marker, the position the storage tube is mounted onto the gear case before you remove it, this way when we put it back together we can do so correctly and it wont be 180 degrees out. Then remove the clips on the outer portion of the case, then split the case.

C. Now take the metal storage tube that the mast is in and remove it from the split gear case.

D. Now unscrew the upper black plastic insulator from the top of that storage tube housing using a 14mm 12 point socket, then pull the tube sections of the mast out of that storage tube.

E. Now remove all of the remaining cable and hook from that split gear case. ... Important, ... pay attention to how that hook is mounted into the drum, this way you will know how to install the new hook when it comes time to do so.  First timers I would suggest after removing that hook, practice a reinstall right after you remove it so when it comes time to install it for real you know exactly how to do so.  You will see why later.

How to Install the Mast and cable: 

 First this needs to be done. 

Note: Before you install the new cable you need to make sure the fish hook has the correct curve to it so that it lays into the drum centered, like photo B. If you do not do this it can break the cable at the fish hook when installing or lessen the life of the cable.

How to do this, dry fit the hook like what is shown in photo A, lay the hook on top of the drum and check the curvature of the hook, note that the fish hook is not going to lay into the center of the drum correctly.

Take 2 pliers and gently bend the fish hook so it ends up looking like photo B. Never touching the plastic cable as you do so. Doing this will extend the life of the cable. Do this before you install the cable into the drum.

This is how the hook should look like when installed. It needs to be centered in the drum and lay naturally between the drum walls.

Now How to Install the Mast and cable:  1 threw 7 below.

1. Now without either the mast sections and no cable installed in the gear case, put cases back together and put  ALL clips in place.  Just the case with no metal storage tube attached to it. We are about to time the unit so it runs correctly.

2. Now take the power unit back to your car, FIRST turn your key on and the radio on, THEN plug the power unit back into the power plug and let the power unit run until it shuts off by its self.  Should shut off on its own in about 8 seconds.  Just let it lay in your trunk when doing so.

3. Now after the power unit shuts off, THEN unplug it from the car. AFTER you unplug the power unit now turn the key and radio OFF.  Take the gear case back to your bench.

4. Now GENTLY split the cases and don't move a thing and only install the new cable and fish hook and put the cases back together along with the metal storage tube. DO NOT move anything when you do this including the drum. If you move any thing your timing will be off.  At this point the cable should be sticking out the top of the storage tube when your done.

5. Now take the power unit back to your car, make sure that the radio & key is off, You want to plug in the unit ONLY LONG ENOUGH to draw the cable in until the rod portion of the cable is about to go in. DO NOT RUN THE UNIT ANY LONGER OR YOU WILL DESTROY THE UNIT.  You will run it only for about 2 to 3 seconds.

6. Now install the Tube sections of the mast into the top of the storage tube along with the upper black plastic insulator that holds the Mast in, then screw the tip on.