Car Electrical Troubleshooting.

General Questions
#1

I have a 09 Jeep Patriot automatic transmission with a strange problem I can’t figure out.

I got in the car the other day and noticed the interior light was very dim. I usually keep my key in the ignition, and I must have left it in the ACC position after closing the windows/sunroof. Yep, turned the key and nuthin.

Not the first time for this. I grabbed our charger, hooked it up and charged the battery for a few hours. Still nothing. Grabbed a multimeter and checked the battery and it was indeed charged. My lights all work. But turn the key and nothing.

Coincidentally, when I went to get stuff out of the back, my hatch was locked (I never lock it) and it would not unlock no matter what I tried with the remote. There is no traditional keyhole.

A friend suggested “resetting” things by disconnecting the battery. I did that for 6 hours, reconnected it and no difference.
Problem with the key? I grabbed the other key which is never used. It locks/unlocks everything but the gate. It doesn’t start the car. Transmission is in Park, in fact I can’t move it out of park. Turning the key in the ignition I get all the light show that normally happens, then turn it the rest of the way and nothing. The only thing that happens is on the display it changes from “P” being lit up to “P”, “N”, “D”, “2”, “1” all being lit.

Any ideas? I’m outa my league here, and hate having to get a tow. Plus the car is blocking in our lawn tractor…:frowning:

#2

A bad ground in one of your ecm circuits could do this. Try hooking a battery jumper to negative side and then moving it around to engine, frame chassis, ecm module etc. Also check all fuses and manually feel the temperature of your relays if one is hot and nothing is turned on it may be defective.

#3

I’ll try this tonight. I’m measuring resistance?

#4

No, in a test like this you are just supplying a ground in case it is missing. Very unsofisticted and simple test.

#5

Cant help you, but when I saw the thread title, I said to myself, “Another Jeep problem”.

#6

Prior to this Jeep Patriot I was driving Jeep Wranglers. I would buy a brand new Wrangler, put 150,000 miles on it, then trade in for a new Wrangler. Never a problem.

Then I decided to move to something a bit more cushy. In 2009 I traded my Wrangler for a Patriot. My first auto transmission ever. And the entire experience has sucked. Two weeks after purchase, my dealership had Chrysler pull their Jeep sales out from under them. The dealership has sold Jeeps since AMC days. This is my last Jeep.:frowning:

#7

I came home yesterday and messed around with the battery/wiring/etc. then I hooked up the charger again. Ninety minutes later I had to leave for a meeting, so I removed the charger and tried to start the POS and it started!

The meeting was a thirty minute drive away so I drove my Jeep to let the a battery charge further. Seemed like a good idea, but when I shut the car down I immediately tried to start it again and got nothing. After the meeting I called AAA. We got the car started again and he suggested I drive somewhere and have the alternator and battery checked.

So, I went to a National Tire and Battery. After politely declining the alignment special :rolleyes: they found my battery totally shot. Bought a new one and all is good.