1991 Ford Explorer. Would’nt start so put in new batt and starter incl solenoid. When key is in Pro-lock, hear a loud mechanical knock and no start. Remove key from Pro-lock and no knock. In both cases, all electricals turn on. In both cases, after trying to start, there is a rhytmic click coming from under the left dash where relays etc live i their little caves.
HELP! Please…