Myriad of issues...no crank and other issues

[Fastbird]

97 2500. My issues started a couple months ago. Engine started doing the click, no crank. Turn key back on and it would crank. Assumed starter solenoid. Finally wouldn’t start at all. Changed contacts and plunger this evening. Still no crank. Now I notice...backup lights don’t work. Not sure how long this has been going on. Grid heater doesn’t appear to be working or at least the wait to start light doesn’t come on. Fuel solenoid is not opening. Further abs and brake light are on. The abs and brake light have been on and off from time to time so they may or may not be related. Awhile back the passenger window wouldn’t roll down. A month or so later it rolled down and has been fine since. Again, may or may not be related. Headlights don’t dim when trying to start nor do dash lights. But abs/brake light do dim when key moved to crank position.

Checked relays, fuses, etc.

Where to start?
Thanks in advance for any help!

 

[Joseph Donnelly]

clean and check the grounds.

 

[GAmes]

The factory service manual has diagrams that show every ground location on your truck. It sounds like you have good use for the wire diagrams too.
https://www.genosgarage.com/product/dfsm97-print/dodgeram-factory-service-manuals

 

[Vaughn MacKenzie]

Sounds like a failed battery cable. That can mimic that you have power, but as soon as something needs considerable current it won’t be able to deliver.