Why won't the truck start after battery was replaced?

Did you get the key switch checked out ? The dash indicator lights have to be on for the engine to start. So you are not getting power to the dash lights, and probably not to the computer or ignition coil either.

Through your own admission, you need
to go to a repair shop, which one would
assume, you always go to

I had a similar problem a few months ago. Ready to get major engine work done, got fire, timing was right, getting gas.....
An experienced mechanic asked where the car had been parked and how long. I had parked it in grass, over a wet spot. The battery was dead too. He told me to park it over a warm spot for a few days and try a new battery. Did that, with the hood open, replaced the battery, and it fired right up. Something about being too damp and/or the voltage in the battery was too weak.. All I know is it worked, and I drive it every day and don't park in wet grassy spots.

Now that a mechanic, I assume tested your car & told
you what was needed,why are you here?

check your alternator check battery see if battery is charging.

That suggests that the problem is in the harness, something in the connector or wiring is causing an open circuit. You will need to have the circuit tested to find the fault. Ford alternators have known connector issues & new aftermarket connectors are readily available at most auto parts stores.

The next time it won.t start tap on the PCM and if it starts then replace the PCM.There has been problems with the PCM.s on these jeeps.

it probley shorted out the brain box

does the van stall going down the road or at idle? the won't change gears at 4000 rpm and the no start condition unless disconnect the negative cable sounds more like a computer problem. when the cable is diconnected the ECM and the TCM have to go thru a relearn process which can be some of your issues. have your mechanic do a quick learn on the trans module to see if it helps the shifting problem. the ECM on the other hand can throw out codes that can make you chase your tail and end up replacing every sensor and still have the smae problem. you may want to check for corrosion at the ECM connections.

It is imperative to have a very experienced mechanic performs a timing belt service!! If not done correctly on this vehicle, severe engine damage may occur. I would recommend checking the cam position sensor, this controls spark!! If damaged or disconnected, you will experience a "NO START" condition!!