car in discharge
something has to supply 12 volts to the system..if you take the battery cable off when its running and it stalls,the alt is bad ( new or not )...but if you had it out 4 wheelin..check wires to starter also..there could be a problem in the loop.
Do you have any other problems? Like is the battery light on showing the alternator not charging? If this is your only symptom then just stop doing it. This test doesn't work on all cars anymore.
Search Chevrolet Blazer Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Chevrolet Blazer Experts