Rev counter/Battery warning

Hi
I have a Disco 1 which on occasions, perhaps twice a month, starts up fine in the morning except that for a few minutes the rev counter does not work and the battery warning light is on. Seems to clear after a short ride... really not sure what could be the problem.. any suggestions would be appreciated.

isnt the rev counter done on a voltage sensative switch? no volty volty no switchy switchy?

then again im normally wrong

if its a diesel, dont the rev counter pick up pulses of the alternator ? which also lights the warning light ?

first port of call, check connections on alternator me thinks !

Usual problem .. connection on the alternator is mucky .. remove it and clean/replace or remove it, cut off and replace with new connector.

New connector is best.