At the beginning I would say sorry because of my english, especially technical words.

I have a big trouble with my Pacifica from 2005. Car was stay on backyard for a week. There was a bit cold (about 10C below zero). When yesterday I tried to go to shopping, I noticed that it was a big problem wiht my car. After turned keys to ON position, the dashboard didn't light up. The engine started normally and then dashboard lighted up, but every sign on it were light on, and headlight were on (despite the ****ch was on the off position). Also any of electrical features (like car radio, windows, door lock, backlight etc.) didn't work. There is also problem with gearbox, when gears are changing the RPMs are drop and sometime engine stops. When gears are changing there also something is happening with electric, because lights on dashboard flashing. And when the engine stops and keys are out the dashboard are still light up .

I have read most topics with similar problems and tried the solutions from them, but nothing is work. Fuses are OK, plugs on ECU are also in good condition, I also check a grounded and battery and everything is ok with them. Where can I search for the reason of this problem in my car? Please for help

 

ui

first go get a wire brush style battery terminal cleaner, looks like a short red bull can. Costs $3 at autozone, or pep boys, or advance. I like autozone. Also get the 7$ socket set if you don't have tools, and a can of wd-40 $4. Also buy a 26" or longer black 4 Guage battery cable. Costs $9. You can return it if not needed.

spray wd40 all over the battery terminals, then disconnect one at a time, first use the bottom of the tool to clean the battery posts. Then unscrew the top and use the cone shaped wire brush to clean the inside of the battery terminals, really take time to get to bare metal . Spray more wd40 and tighten
them hard.

if that doesn't fix it, try this test, put one black jumper cable on the negative battery terminal, and clamp the other end to the frame of the car, on a bolt, or where the hood latches ,anywhere you can get bare metal. If that fixes it, or even gets your lights to flicker, it's a bad ground, here is a quick fix.

This fixed mine--- take off the nut on the negative battery terminal where the O connector cables/wires connect, clean all of these too, attach the 26 inch 4 Guage black battery cable with them, tighten well.
in the front of your engine you will see a 10mm bolt with 2 or 3 grounds, take the 10mm bolt off and attach the other end of the bartery cable there. You can't have too many grounds!

I had a similar problem, and my starter turned over very slowly. The problem was bad grounds. The main one that goes bad is behind the drivers side plastic wheel well, turn wheel all the way to left, and pull out hard plastic thing, it's a 15mm bolt on the transmission that corroded from snowy roads.

9 times out of 10 it will end up being dirty, corroded or loose battery terminals. But our cars also break main grounds, especially if you live in snow.

please post if this helps.

you can also try just cleaning the terminal's with scotch Brite sponge and salt water or sandpaper or whatever you have. Bet you a doughnut it's terminals or ground.