Hey guys, I've had my mav for about a year and it's always had a problem with the battery randomly dying. I can usually drive it normally for about a week or two until it ends up not having enough juice to start. I have checked quite a few times and Im 90% sure theres no drain. I have already removed the door-ajar buzzer. The battery, alternator, spark plugs, and spark plug wires have all been replaced by me. The alternator was a rebuilt one from oreilly, everything else came brand new. A couple symptoms: I've noticed it's a bit low on battery after about a week of normal starting and driving (it read about 12.5 volts, its usually 13.5ish on a full charge); it managed to start but oddly only read around 11 volts while running(?). I have a stereo/amp/sub/4 speaker setup, and the car doesn't like when I even use my wipers,heater, or headlights while the stereo is on. I've heard a few rumors that regulators can go bad and cause problems like this, but I have no clue how to test it, and the one that came on my car looks pretty clean and new. I have done the pull-a-fuse-and-test thing to try and find a drain, and that didn't show anything (although i'm not entirely sure I was doing it right). I've gotten a few tips from shop guys that it sounds like a charging system issue, but mostly everything in my charging system is new so I have no clue what to test. If anybody has any thoughts or tips, they're all appreciated! Im hoping somebody can save me a $75 diagnosis fee that might not even find anything :/ Thanks for your help!
Providing you've had the battery tested already......... I know its a little bit of trouble, But personally I would take the alternator off and back to O'reillys and ask them to bench test it on the machine. If it tests good, purchase a new voltage regulator before you leave, they are not that expensive.
So I should test the battery and alternator and if neither of those are the problem, then just replace the regulator?
Did you buy a new alternator wiring harnes that plugs to the alt and the volt reg mine had a broken wire inside it so i had to rplace it
A broken wire in the charging circuit will not keep the vehicle from running. What does the voltage read when running? Did you inspect and check the connection of the regulator? Might unplug it and plug it back just to insure a connection..
I tested the battery this morning; it read about 12.5, then 11.5ish while running, then about 12.3 after I turned it off. Ill take a look at the regulator and make sure its connected well.
Save this to your desk top or somewhere.. May come in handy some day. http://1bad6t.com/Maverick/repair/chassis_electrical_05.html
If voltage decreases with engine running the charging system is very weak at best... Easy test is check voltage at idle and then at 2000 RPMs with load(headlights, heater blower, windshield wipers, sound system etc), if voltage increases as you turn off items alt has low capacity or just isn't large enough for the job...
Here's an easy test to see if your alternator is good. With the engine running jump the "A" and the "F" terminals in the regulator plug. Do this with the plug disconnected from the regulator. The voltage should rise quickly tested at the battery. Do not let it go over 16V! If you do not get a voltage rise, make sure there is power at the "A" terminal.(should be hot all the time) Also check for a burned out fuse link to the B+ connection on the alternator. You should have power to the B+ connection at the alternator too.( should also be hot all the time)
Also make sure at the harness going int the fire wall is pushed in all the way. Other wise you have no connection on the inside of the car.This was my problem.
