The computer can be reset using an OBD-II code reader/diag unit. If the light returns then the code must be read to determine the real problem. Run1 When the battery has been disconnected or replaced, it clears the on board computer of all errors and all data. The inspection station uses data from the OBDII computer to check if the car is within compliance, so when the battery was replaced all the data was cleared. You will need to drive the car roughly 50 to 100 miles so the computer can read all the sensors on the car to see if they are in good working condition or give you another "Check Engine Light".
Disconnect the vehicles battery. Leave it unhooked for several hours. Reconnect the battery. This should reset the 1989 cougars computer.
timing is computer controlled there is no way to advance or retard the timing without changing the chip in the computer
How do i find the instructions for changing out the fan switch assembly in a 2001 Mercury Cougar?
check the cables
It's grounded on the front of the Mercury Cougar frame next to the headlight assembly.
The dash clock in a New Edge Cougar does not turn off, unless you disconnect the battery.
I can tell you that on a 2000 mercury cougar it is a fuse on the positive cable between the battery and the alternator
go to a auto parts store like advance auto and have them check your computer to see why it is on. they do this for free. this might give you a idea on why its on. if you havent already.
On a UK model it is under the bonnet next to the battery.
The computer control module for a 94 Mercury Cougar is located behind the glove compartment. This allows it to be accessed easily while protecting it from damage.
The ( Power Distribution Box ) is between the battery and the driver side fender .
the battery could have a dead cell, this could cause it to not charge. Have the battery tested to be sure.