New problem on my 96 disco 1. Driving I will all of a sudden have tach drop to zero and the battery light come on. Speedo keeps working, stereo keeps working, Scanguage keeps showing correct RPM (so not an issue with source being sent to ECU). Then seconds later starts working like nothing happened. Battery voltage indicates alternator is working properly (and no issues with other electrics when this happens)

The intermittent nature of this is classic lose connection/solder joint that needs to be reflowed. But, I don't have the time or energy to start ripping apart the truck or search schematics to figure out where. I actually usually enjoy electrical scavenger hunts but am very done with the disco...

So, interested if anyone can point me some low bearing fruit to check out in the hope I can quickly find the problem!

 

Belt slipping possibly. Check the belt, the idler pulley and the tensioner. Had the same thing happen on a Case tractor with a new V belt, it was raining and the belt was loose after initial stretch. That's about as low hang'n as your gonna get I'm afraid.

 

while your adjusting the belt - pull it off and see if the alternator spins freely. I ended up replacing mine (dropping tachometer led me to it) due to bad bearings - would barely spin and wined like hell.

 

my tach would bounce all over the place, lights would flicker occasionally too. replaced alternator and it settled down