Ok, first a little background on my truck. 04 GMC Z71 with Radix, Magnaflow cat-back, ect. 43,000 miles, no trouble at all so far.20,000 miles on the Radix install. Never been back for warranty work (none needed)all maintenance been done religiously. In May, I installed an Alpine head unit, new speakers, and powered sub. No outrageous amperage, no extra amplifiers. Everything works fine. 2 weeks ago, the truck sat for 2 days (I'm working out of town, and drive a work van from the hotel to the jobsite.) I go out to start it, and NOTHING. Not a click, peep, or hint of power at all. Luckily, I could jump it with the work van. Next day, I go to Sears Auto to get an Optima. I figured if I gotta buy a battery, might as well go with the best. They did the charging systems and battery test, and said everything was good, no need to buy the Optima. Being out of town, and kind of vulnerable, I bought the Optima anyway, just for good measure. Well.......yesterday, after the truck sat for only 1 day, the Optima is now dead!!! Jumped it, and grove it around for a few hours, everything seems up to snuff. BUT......what could my problem be? I don't have my install instructions from the head unit, I'm sitting here trying to diagnose it before I go home next weekend. Any ideas???

 

Sounds like there's an excessive parasitic draw...You need to get a multimeter set to amps and hook it in series with the negative cable...anything over 50 milliamps is too much. At that point you can start pulling fuses one at a time to isolate the circuit with the problem. Pull a fuse and observe the meter, if the draw goes down, you've found the circuit, if not, re-install the fuse and move on to the next one. I'd check the circuit associated to the aftermarket head unit first

You can get a multimeter at Sears for less than $50. Also, if you do a search for some of greentahoe's old posts, you may find more info on this...I remember that he had a similar problem a few months back I believe. Good luck!

 

Thanks, I'll try that. There's just something in the back of my mind that points to the head unit adapter for the retained accesort power, and chimes.. I never did like the chimes from the adapter you need. I still wonder why it only took 2 weeks, to kill the Optima.

 

If the draw is big enough, it'll kill a battery pretty fast (kinda like leaving the headlights on)