Have to unplug the battery to get my car to start. Dealer can't figure it out!

I have a 2008 Dodge Caliber and recently we have had some problems with the electrical system in the car. We had some cold weather this winter and it would not start, not turn over, nothing. We finally though that it may be the anti-theft system and unhooked one terminal in the battery, turned the key in the lock a few times, and it started! It ran fine for a few months, no problems. One day, on the way home from work, the electrical system went haywire, with the speedometer, RPM gauge dropping and resuming, and the lights flickering. We made it home and the car died and would not start again. The next day, we unhooked the terminal from the battery, started it up and took it to the garage where they could not duplicate the problem. It ran fine for a few weeks and has been happening every once in a while. We have been dealing with the problem and just unplugging the terminal if it gives us a problem. Anyone have any ideas??

It is now July and very hot and it would not start again. When it will not start, the lights will not work, the doors will not open with a key and nothing electrical will work.

Have you traced the battery cables? If there’s a loose connection or the wire is broken, then you unhooking and then re-attaching the cable might be wiggling it back into place so that you get a connection, if only temporarily.

That electrical system going “haywire” is a sign that points to losing all electrical power momentarily. Start with the battery cables and be sure they’re snug on both ends, aren’t broken somewhere in the middle, and don’t have frayed insulation that’s allowing the wire to contact something metal.

The anti-theft and remote start systems if equipped would be the first suspects…

+1 to Caddyman’s comment.

I went through a similar experience with wifes windstar, after removing the instrument cluster to look for cracked solder joints, there were none and noticing leakage around one of the posts, I gave the terminals another heck of a good cleaning and replaced the battery with an 875 cca rating. 2 months and no problem since. I am going to replace the terminals soon, as there appears to be some corrosion after I cut back the rubber boot that protects it.