Here is what I posted:

Yesterday I installed a cruise control from a junker in my 1987 745. Apparently all 7xxs are prewired. The whole operation is more intuitive than you would think from my description. It went without a hitah and took a leisurely 2 1/2 hours.

Here are the details:

Engine compartment:

1. Replace the accelerator crank (the round aluminum wheel). The new one has 3 grooves. The kickdown to the transmission goes on the inside, the accelerator in the middle and the cruise control will go on the outside.

2. Bolt the bellows to the intake with two 10mm bolts. The threaded holes are below and behind the accelerator mounting on the intake. There is very little space so it's rather awkward. Disconnect the hose that's in the way to get access. Connect the cable to the accelerator crank.

3. Mount the vacuum pump to the front strut tower apron. Drill 3 holes to do so. Plug in the wire that's somewhere near the strut tower -it's easy to find. Do not use the engine vacuum!

(I understand that this applies to 85-87 models. For 89-90 models the vacuum pump is mounted on the inside of the strut tower under the master cylinder. Bracket clips in, install one screw to hold.)

4. Remove the grommet just above and to the right of the brake booster. From inside the car (after removing the knee pad to get access) feed the hose into the engine compartment through that hole so that the delete switch is inside the car. From the engine compartment install the new grommet so that the hose goes through it.

(Re)connect the three hoses to the tee.

Inside the car:

5. Install the delete switch in front of the brake pedal through the round hole in the bracket. Plug the small flat plug with two wires into the delete switch.

(This is for an automatic. You need a second delete switch if you have a manual gear-box.)

6. Install the black box near the hood release lever. My car did not have the dedicated bracket that I understand some 7xxs have there so I just screwed it onto some other existing bracket. In the harness nearby find the plug and plug it in. Find the single yellow- red wire and plug it in.

7. Install the turn signal arm. Plug in both plugs. To get access you will first have to remove 4 screws to remove the covers and then turn the wheel to get to the screws on the switch.

8. Test on a quiet road. I did not have to do a single adjustment. It worked perfectly right away.

Thanks to Brian Leppin for his instructions and for selling me the parts (around $100).