This is likely that this is an after market installation. You should start by checking the power and the grounding.
what is the firing order for a 1987 mercury cougar v8
You can find the correct firing order for your 1987 mercury cougar at www.coolcats.com, it is a website dedicated to the cougar and thunderbird.
CID?
They Call Me Mr. Trunk was created on 1987-12-17.
yes
If I remember right, it's in the glove compartment, on the left side beside the power trunk release.
I have a 1987 Mercedes that has no trunk key. Do I remove the back seat to get in?
a fuse, relay, bad ground or positive wire at switch or solenoid, etc.
According to a website I was looking at : For a 1987 Mercury Cougar , 3.8 liter V6 , 4 speed automatic transmission ( 17 city / 24 highway , miles per U.S. gallon )
To open the trunk on a 1987 Porsche 928, locate the trunk release button inside the car, typically found on the driver's side near the door or on the dashboard. Alternatively, you can use the key to unlock the trunk by inserting it into the trunk lock located at the rear of the car. If the trunk is stuck, check for any mechanical issues or consult the owner’s manual for troubleshooting tips.
1987
right frame rail near fuel tank.