Its right under the driveside of the dash.. near the fuses
Passenger side fender near strut tower
under the dash on the drivers side you may have to slide your head under and look,on the left hand side by hood release
Under the steering wheel. Where the plastic ends in the foot compartment and on the left side of that. Just a little bit towards the front of the car from where you left knee is when driving.
View the link below.
It should be under the dash on the drivers side.
where is diagnostic link connector for Honda odyssey 2005
The diagnostic link is behind the ashtray,which you will have to remove to get to the connector.
The DLC (Data Link Connector) should be found under the drivers side of the dash. It has to be within 18" of the steering column by law.
Click the link.
To my knowledge there should not be a diagnostic link on a 79'. most of the d100 trucks have a diagnostic port on the drivers side inner fender
For a map of the range of the cougar, click on this link.
Diagnostic plug. Diagnostic connector. Data link connector.