Battery Won't Change
 

Battery light came on gauges went dead and truck stopped. Installed new alternator. Battery light still on and truck dies after several minutes. What do I look for now?

So the battery is strong enough to start the truck but it won't stay running?

Check battery terminals and grounds, could even be bad battery cables, they can corrode internally and cause all sorts of issues.

-Steve

Thread moved to electrical section

Check the connector on the alternator and make sure it's not damaged and the wires aren't bad

Should have asked, what year truck?