No power to anything good battery fuses are good

THE CARS MAIN BATTERY IS DEAD.
WHAT IS THIS TENDER THING, A BATTERY CHARGERS/?
YES , HOW MANY AMPS IS THIS CHARGER?
MAIN BATTERY DEAD.
BATTERY LUGS LOOSE
BATTERY LUGS RUSTY, 2 CABLES 4 ENDS NOT RUSTY
OR BLEW UP HUGE FUSES./

TENDER MEANS? WHAT? NAME IT AND MODEL, FOR BEST ANSWERS AND IF WIRED BACKWARDS.

If there is NO power to ANYTHING, suspect a cable issue/connection. If there is some power to some accessories, possible fuse link blown at starter area. You may need to do a voltage drop test to determine the source of the problem on the battery cables

after each step below check for power:
1. make sure you have a good ground. tighten battery negative if loose (also at the other end of the cable.) (tighten also the b+ if loose)
2. temporarily disconnect the wiring to the alternator. (tape any exposed wire.) (to verify if the alternator is not shorted)
3. check the ignition switch.

Start with the battery. Make sure it is at a full state of charge, at least 12.6 volts on a voltmeter. If it is under 12 volts have it charged, or if battery is over 4 years old, best to replace it.

With a good battery, clean all battery connections. Get rid of all corrosion so you have a clean metal to metal contact. A solution of water and baking soda helps a lot. Replace questionable battery cables. Then get a good tight fit on all cables, battery, starter, and ground.

Now if you still have no power to anything, lights, or switch, horn, anything...then you will have to find the fusible links just off the battery that distribute power to the head light switch, to the key switch, to parts of the fuse panel, etc. If fusible links blow, they can be cut out and replaced. They act like fuses, designed to burn out to protect the rest of the circuit from burning up from a short or amperage surge from a shorted electric motor. Once you get power to the lights and the key switch, you should be good. Go from there.

well first of all. check main fuse in fuse box. to check alternator--- with car off at battery, voltage should be at least 12.5 to 13 volts. then when running. there should be at least 14 volts or a bit higher, at battery. but it sounds more like a fuse then anything else. if all is satisfactory then check to see if power is going through ignition. have a good one !!

CHECK BATTERY VOLTAGE ITS SHOULD BE 12.5 VOLTS.IF YES.I AM LOOKING AT BAD GROUND BATTERY CABLE OR LOOSE CORRODED BATTERY CABLES.REPLACE THEM IF THEY ORIGINALS CABLES.TURN OFF RADIO FIRST BEFORE REMOVING BATTERY CABLES.IF BATTERY AND CABLES GOOD.CHECK IGNITION POWER FUSES AND ALTERNATOR FUSE.IF ALL LOOK GOOD.YOUR ALTERNATOR COULD BE BAD OR A OPEN IN IGNITION SWITCH COULD BROKE OR LOOSE WIRE IN SWITCH.

Check main fusable link or fuse (on small wire from + battery terminal

Sounds like a bad connection with one of the battery cables check the connection to both cables at both ends and I personally would make sure that i cleaned the main engine ground (where the negative wire from battery connects to engine). Good luck!

Check battery and chassis earth connections are ok.
Check for 12v power at the fuse/power disrtribution fuse bus; - if no power there, trace circuit wiring back to battery.

i think it has 2 boxes. but id look at the ignition switch. do the headlights work. and is there a big fuse very close to the battery you might be over looking. and a lot of time the fuse box gets power from the starter. check to see if you have power there. and does this truck turn over good luck