Since it has started getting colder out my blazer wont start w/o a jump sometimes. I can hear the starter ticking but nothing then the weird thing occurs affter releasing my key from the egnition the interior lights will flash and the rear gate will open up :/ . now I have had the battery tested, the fluids topped off and all seems to be good.

When I finally get it started from a jump the rpms will go up and down when its idle and the dashboard lights go dim then bright nonstop.

Could it be the alternator?

thx

 

Sounds like an alternator. If you can get it to start (or charge the battery and start it) normal behavior would be turn the key on and see about 12v on the voltmeter. When you start it after about seven seconds you should see the voltage rise to 14-15v (depends on how cold it is). The alternator has a "soft on" regulator. Before you replace the alternator check the single wire connector going into the side of it, if it's corroded or loose it could have the same effect.

 

problem fixed went to get my alternator tested while there they inspected my battery again(different shop then the 1st) it turns out my alternator is good but my battery had a bad cell in it.
thx ronjon for your help thou