Got a new problem that is pretty old. The vehicle was originally owned by the fire dept..and they had it specially "pimped out" with a high amp alternator to accomodate all the battery chargers and such....the alternator seemed to run all the time, and kept draining the battery.Replaced the battery-same thing -battery would die. Tried to change the alternator,but the wiring was also "pimped" and was not compatible with a "normal" alternator, so my husband had the "pimped-high-amp alternator refurbished.....didnt work! My husband has been hooking it up to a battery charger every night for over a year so that it will start in the morning.
We finally got a replacement "original" wiring harness and a "normal" alternator installed- it started right up FOR ONLY 2 DAYS!!!
UGH!!! Back to being stressed over car problems and back to being broke for the same reason!!
The battery is 2 yrs old...do you folks think that it needs to be replaced...that its worn out from all the dying and charging???
Any other ideas as what to do next???

 

It is possible the battery is toast now. I would get it tested just to double check. You can also bench test an alternator at most auto parts stores...

 

we have had the battery tested,tho not very recently..the alternator is brand new,so why would we want to test that ?

 

Test the battery again and replace if needed. I would do a parasitic draw test - you can search here or google to find out the process. See if there is in fact a drain then isolate where the drain is coming from and repair...

 

was the battery fully charged when the new alternator was installed ?
Newer alternators do not like charging up dead batteries ,it tend to cook them

If you have a hand held volt meter this is how I would do some basic testing

fully charge battery with a battery charger before doing any of this

connect volt meter to battery ,key off voltage should read at least 12.6 volts
Start vehicle with volt meter connected , voltage should not go under 10 volts while cranking to start if it does replace battery
When running the voltage should go back above original 12.6volts ,turn headlights on and heater fan on high voltage should still stay well above 12.6V if it doesnt you have a alternator or wiring issue

 

We replaced the battery, and now the blazer is starting up- like a normal car! Woohoo!. Thanks,everyone for your input..so glad I found you guys!