On the drive home from work my battery light came on and it dropped to 12 volts. By the time I got home it was down to 9 volts, blinkers were barley working but I made it. I thought it was the battery because my current one was old so I switched it with a newer one. Now it stays at 12 volts, won't drop below that even if I drive with anything on, but it won't go above it either. Did I put a battery that's to small in? I have no idea what the amps are, there not labeled. Or is this a sign of my alternator going? Thanks.

 

i have a new battery and a new alt and it stays at around 12 volts, however i am not sure there isn't something wrong with my system...just my

 

Is your battery light on? Mine has always stayed at 14 volts, can't remember if it was the same with my Blazer...

 

My guess would be alternator. Mine outputs about 14V. I image the battery could continue outputting 12V until it is nearly drained.

 

Well I guess tomorrow after work I'll try my alternator from my Blazer, hopefully that works.

 

Dammit, an alternator from a 95 blazer doesn't quite fit, go figure. Well I guess I'll take it to get tested. Will post results.

 

It's your alternator for sure,don't even bother testing it.
Do youself a favor and buy a brand new one(not a remanufactered)if at all possible.
The remans just dont seem to hold up any more. A new one cost me about $125USD
about 6 months ago. Good Luck!

 

Yeah, I got it tested, sure enough it was hooped. Going out to buy another one later, $165 with trade in, so not to bad. Just sucks about the Blazer alternator, it's working just fine. Oh well, time to part out the Blazer and get a bit of cash.

 

Well I put the new alternator, put in a charged battery, turned the key and nothing. No power, everything is grounded, the battery sparked when I connected it, so now WTF? Is it possible to fry my electrical system without a battery? I even tried my older battery and the same result.

 

Well I had a second look and my and my infinite wisdom hooked up some ground cable to the alternator, and left the power cable off. I noticed it and switched it with the power cable and still nothing. Put the battery in a car and it fired right up, so I know it's not dead. Where does this ground cable go? I connected it to a few spots. It ties into a fatter cable that goes to a few other places on the engine.