Had a weird one happen today.....coming home from a trip, 98 degrees out, about 75 mph going up the interstate. All of a sudden every light in the dash was either on or flashing. Lost power, then motor died and coasted to a stop. Had absolutely no electric when I shut the key off and turned it back on. Made a call to be picked up and while waiting, periodically tried ignition. By the time the ride got there, had power when ignition switched on and starter clicked. OK, the battery went dead, so went and got battery, switched them and started right up. With one glitch, red battery warning light stayed lit after start up. Drove it home and shut it off to let it and me cool down. Went back out later and started it up, starter had a little drag and light still on. Any ideas? I am assuming alternator but I am not familiar with LR alternators.

thanks,
rmcc

 

Yup, alternator (or bad grounding cable).

 

Check the small wire that goes to the alternator. Tighten or fix that connection if it looks bad or crusty. Then check the output on the alternator

 

That light means simply that the alternator is not putting out volts greater than the battery voltage. The reason your truck died is that the alternator failed and the truck ran on the battery only until the battery discharged fully or near fully. The same thing happened with my truck in May when my son was driving home to Charlotte from Wilmington. He called about half way (100 miles from home) and said the M&S lights were flashing. There wasn't much we could do at that point (he was pulling a U-Haul trailer) so I told him to keep going. He got to within 5 miles from home when the truck died. I replaced the alternator and recharged the battery and all is now good.

Also, the small wire on the alternator runs from the No Charge warning lamp and is grounded via the alternator to the alternator mount. When the alternator is putting out volts greater than the battery voltage the light goes out.