Usually when I start up and drive my Gryphon tuner has always read 14.0 - 14.2 battery voltage. Since yesterday on startup it starts at about 12.6 volts and increases to and holds at 13.8 volts. I have added new DDM HID's and had to change a fuse on my tail when I crosses the LED tail wiring. I have checked the install of the HID's and everything looks good.

 

First thing to do is confirm your tuner is accurate. You know ? Meter it yourself first to confirm. Next, temporarily by pass your latest modification, - if that's when the trouble started and if you can. That stuff won't cost you anything but a little time. From there, you should go thru your cable connections. You may want to do that first, that won't cost yuh either. 14 + is running current btw. Check the battery before you fire it up, then check it running. Keep in mind your alternator housing is absolute ground.

Good Luck.

 

1. Perform the SScully Battery Test: https://www.f150online.com/forums/4380878-post18.html

2. Get rid or that crap DDM garbage. (fyi - See sig for the proper way to do HID's.)

3. Good luck. My bet is on the battery starting to migrate south fer the winter, lol.




MGD
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Really great info guys. Thanks, i am going to start some testing this weekend.

 

Not quite...



The alternator case combined with the battery (-) post together form the true ground for the vehicle. If they're not connected properly, then there is no true ground.

 

Right! It should be. Nice write up from that site(Alternator/Rust,corrosion@the bosses/CrownVic). Thanks, that one slipped my mind. I have a 04 grand marquis that I need to go thru (PW's motor/all/very slow). That will be a good place to start.

BTW, I also liked this post here, -

there have been scattered reports of people on this message board getting several "bad" alternators in a row from the auto parts store. if you've got corrosion like pictured above, you can install all the alternators you want and still not have the charging system work properly.


Yea, just something I didn't think of.

 

|!"/$%?&*()_ now I have to go out and clean the alternator grounds.