You don't need to hook up an ACT sensor. You don't need to hook up the BOO. These instructions are only the basics, not a how to write up. There are more detailed instructions at the Merkurencyclopedia.com. These are the pins that you have to move to put an LA3 into your Merkur:

Note: YOU DO NOT NEED TO DO ANYTHING TO KEEP THE CRUISE CONROL WORKING. THE CRUISE CONTROL IS COMPLETELY SEPARATE FROM THE EEC-IV IN A MERKUR. NO MODIFICATIONS ARE NECESSARY!

1. Pull out pin 43 and move it to pin 27. This connects the VAF signal. 2. Pull out pin 25 and move it to pin 43. This connects the VAT signal. 3. Pull out pin 32 and move it to pin 31. This connects the boost controller. 4. Pull out pin 35 and insert it into pin 33. This connects the EGR solenoid signal. 5. (NOT NECESSARY)Put a spare pin into pin 2 and connect it to the side of the brake pedal that is not hot unless the brake pedal is depressed. This is the BOO signal for the Turbo Coupe EEC. 6. (NOT NECESSARY)Put a spare pin into pin 25 and attach it to the colored/striped lead of the ACT socket that you installed. Attach the solid colored lead of the OEM socket to a good ground. This attaches the ACT signal to the Turbo Coupe EEC. 7. Put a spare pin into number 24 and run it to Signal Ground which is pin 46 for permanent premium mode. Or install a switch so that you can switch between premium and regular modes.