"Charging System" light ON
 

Hi guys!

95 4x4, 4 dr blazer.

Charging system light just came on this morning when I started the truck. It's the "idiot light" on the left side of the dash that lights up red in the shape of a little battery.[:'(]

Truck starts and runs fine.

I've pulled and checked the battery terminal connections. Minor corrosion on the positive post. Cleaned and reinstalled. Light still on. Battery was new about 6 months ago. Belt tension seems fine.

Any suggestions on diagnosing????[sm=helpout.gif]

Thanks!

RE: "Charging System" light ON
 

Connect one lead of a voltmeter to the positive battery terminal on the back of the alternator (there is a stud with a nut holding the battery cable on the alt.).Connect the otherlead to the case of the alternator. With the engine running you should measure at least 13.5 volts DC. If it's less than that the alt is probably bad (take it off and have it bench-tested at your local parts store), but it could also be the ECM is not turning the alt on, or the wire it uses to turn on the alt is bad. Most likely a bad alternator though.

RE: "Charging System" light ON
 

I was driving down the freeway, many years ago, and my charging light came one. For some reason, I just assumed there was something wrong with the light and I kept going. About 10 mins later, I was on the side of the road with a steaming engine. The fan belt had broken and alternator stopped rotating (along with the water pump.). I don't ignore those lights anymore.

RE: "Charging System" light ON
 

Conducted the suggested test with the voltmeter, as well as some suggested by my Chilton manual. Results led me to believe alternator was toast.

R/R'd the alternator with a remanned one ($119). Dash light out now, dash volt guage reading nearly 14 volts. Problem solved.

My work here is done. Time to head to the hot tub with an adult beverage.[sm=icon_cheers.gif]

Thanks for the help guys![sm=gears.gif]

RE: "Charging System" light ON
 

No problem Willy, glad you got it fixed. Don't have too many of those "adult beverages". Is that possible?.....lol