Should be two wires dangling left of the clutch pedal, probably behind the mat; One spade, one socket. When joined
turn the key to the "on" position (not running) and the engine light will flash the code for any anomalies. First code will be "12" (one, one-two) which will flash three times before any other codes come up.

'89 P'up, 2.6 I-Tec, 488,000 miles and done... gone to the great beyond