Is the charger gold or black? Gold is old and black is where it's at. The gold charger will have a loud fan noise as the blacking e will not. When it's turned on. Those chargers will not turn on unless they see over 18 volts. You need to check your volts at the battery connector. Black on negative and red on positive. Checking DC voltage. Sorry I don't know how green you are or anyone is for that matter. If below 18 volts you need to truck the charger. You can do that by grabbing another truck (pallet jack, epj, wp). Take the battery connector from the good truck (battery side) and plug it into the bad truck (truck side). This will give the bdi a false service charge reading. Let it sit for a few minutes. Then disconnect and plug connectors back to normal positions. Use all safety equipment required for handling battery's. Then plug in charger and see if the fan turns on now. Or check your volts at the connectors again. See if it goes up from what ever it was at. You really need a dc amp reader to do this properly. Because sometimes the chargers will be putting out the volts but not the amps. If this didn't work. Get the trucks next to each other again and plug both battery packs into each other. While wearing safety gear. This will charge the other battery pack. The battery's will balance out. Let it sit for like 20 minutes. Then plug back to normal and try charging. If it's over 18 volts and still nothing you have a bad charger. There are more options as well. You just need to get creative. Let me know if that helps and if it doesn't I have more things for you to try. Good luck.

***Update***

I managed to get my hands on an onboard charger from another unit and after swapping in the charger the unit now works. If the charging unit is inop or cooked the unit will do nothing MAYBE display hours if that. Thanks to those who offered advise ??

I appreciate this and will try it Monday thank you.

I am familiar with these trucks, but have not had any charger issues previously. All these newer machines disable the truck when the unit is charging. On other brands, you can connect the small wires together at the key switch so the machine will start up. If that works, then the charger is the reason it wont turn on.

Ah, I was thinking it was a much older machine. I'm not familiar with the setup you have. You might want to try searching for online manuals or contacting your local Crown dealer for a service manual.

My apologies for less than adequate info. The unit has a charger to the left side of the drive wheel with the hydraulic pump/motor to the right. the battery is new and sits in the middle of the Jack separate from the motors internal wiring and module. The main cables come in from the batter connector and run along the top to the module however the 10 amp fuse and the key switch is actually in line through the charger itself.

Newer versions of the charger look like this but this unit is a bit older and has the brass casing with no heat sinks

https://www.crown.com/content/dam/crown/images/products-page/forklifts-page/pallet-trucks/wp3000-onboard-charger.jpg

I'm assuming this is a jack with the charger in the middle and two batteries on each side. Be sure that all four batteries have enough water to cover the cells before trying to charge. (if you're using flooded cell lead acid batteries)

The onboard charger is a completely separate unit from the pallet jack wiring. If your charger is bad, the batteries might be too low to run the jack. Measure the battery voltage at the connector both when trying to run and when trying to charge. It should charge at at least 25.5 volts. When trying to run it shouldn't drop below about 20 volts.