Sounds like the battery is not accepting charge. As batteries fail(normally due to sulphation), they get to a stage where they will accept a "surface charge",which would explain the 5min. delay, as the high discharge rate caused by cranking will cause the battery to accept "surface recharge", but after this there will be no further input possible from alternator. Another possibility is the regulator having a heat related issue.It is possible (if your alternator was 'reconditioned') that the original regulator was re-used(probably tested ok 'on the bench')or alternately the vehicle may have an external regulator, which was overlooked in the repair process.The only other possibility I can think of would be the diodes in the alternator failing under heat stress. Having said that, I am a mechanic, not an auto electrician, and a little drunk at the moment..:)..but no doubt there are other possibilities, hopefully someone else might have other contributions..has the charge rate actually been physically checked when the light is on?..
BTW, i think I overuse the word 'possible' way too much....possibly..:)
pomandrew, April 2009
