Batteries and fuses good and believe relays are to. When glow plug light goes out and crank all I hear is a click from starter relay, lights do not dim. Suggestions... Thanks

Remove and fully charge each battery. Diesels, particularly in winter, requre strong batteries. Most auto parts stores will do this for free. Clean battery terminals and cable connections. Examine cables for corrosion. If the problem persists, clean the cables and connections going to the starter motor and solenoid.

I installed 2 new batteries and cables look good. Truck has low milage, 47k and warranty ran out in march 2011.

If the starter motor doesn't turn, but the starter solenoid (relay) "clicks" when the ignition switch is turned to Start, the problem is with the battery, starter solenoid, or starter motor connections.

In order to check the solenoid, put the transmission in Park and remove the push-on connector from the solenoid “S” terminal. Connect a jumper lead (12 AWG), or preferably a remote starter switch, between the positive battery terminal and the exposed “S” terminal on the solenoid. If the starter motor now operates, the solenoid is fine and the problem is with the ignition switch, neutral start switch, or wiring. If the starter motor still does not operate, replace the solenoid.

The click I hear is from the interior fuse box, full ISO relay starter. Checked fuses with test light, all fuses in power distribution box tested OK. Interior panel w/ key on all passed except for:30-15a high beam headlamps, 31-15a starter relay, 32-5a radio start 46-10a left-hand low beam headlamp and 47- 10a right-hand low beam, all failed. Head lights low and high work.

Started from ground 1 today, your 1st reply, took all cables off batteries and fully charged again, checked starter wire connection and found lower wire w/ little torque, loose. Hooked batteries back up and she fired. Guess I've just got a case of the dumb asses. Thanks for your time and help. Merry Xmas