Total loss of electrical power when turning off engine

[domct203]

I have a very strange electrical issue with my 2002 XLS, I hope someone can help me.

The truck runs fine, battery is only a couple of years old and is very strong.

Twice now, when I put the truck in park, as soon as I turn the key from run to acc, I loose all electrical power in the truck. Normally the radio will stay on, even when I turn the key to off, until I open the door. Not today. If I fiddle with the key and gear shift, power comes back and the truck starts right up & runs like nothing happened.

When I say all electrical power, I mean everything.... no dash lights, no headlights/parking lights, radio or interior lights.

If I fiddle with the key and gearshift, all the power will come back. What is very puzzling to me, is that I also lost all my radio presets & settings the second time this happened, which tells me the constant 12V memory wire is also loosing power, (or ground connection to the battery I guess).

This happened twice today. Once this morning when I got to work. After fiddling with the key and shift, it started right up, and even my radio presets were still there.

When I went out to lunch, while I was driving the radio shut off and turned itself back on while driving (within seconds), but the truck showed no other signs of error (no battery light etc). When I got to the deli, I had the same situation as this morning. As soon as I turned from run to acc, total loss of power. This time when the power came back, I had lost all my radio settings. When I got back to work, The truck shut down normally.

The only other thing I've noticed is that the steering wheel has a funny 'click' sound to it when turning at a slow speed. Everything in the steering column under the hood is tight, from firewall to rack. Other than this 'click' sound that I hear, there has been nothing different about the truck that would be seen as a warning sign.

When I get home from work I plan to check both battery terminals to make sure they are tight. I know that they are clean, no corrosion at all. If this happens again when I get home, I plan to just let the truck sit and see if it corrects itself without fiddling with the key and shift. I will also grab my meter to check ground continuity, voltage at the battery, as well as if there is power in the under hood fuse box.

Could this be something in the ignition switch?

I've searched the forum (and internet) and the only results I get are related to the truck shutting off while driving.

I hope someone here can help, I love my Explorer, and I'm totally bummed right now....... It's also my daily driver, so I need to resolve this quickly.

Thanks in advance for any help,
Dom

 

[domct203]

Update.

No problems when I got home from work.

I popped the hood and checked the battery terminals. The negative was just loose enough to turn about the post.

I tightened it down, fingers crossed.

Dom

 

[toypaseo]

Check for corrosion between the battery terminal and the cables. I had a turn key, click, and everything dead issue. That corrosion was part of my problem.

 

[domct203]

Thanks, battery terminals are very clean, no corrosion inside or out.

After tightening down the negative terminal, I’ve made three trips with the X, no issues. I’m sure that was it.

Dom

 

[ptf18]

Do you hear the "clicking" before you experience electrical issues?

 

[domct203]

No clicking. Just a dead vehicle, like there was no battery at all.

In my case I’m guessing that the poor ground connection at the battery was enough to ‘reboot’ the PCM.

The truck has once again been flawless at startup & shutdown since I tightened the terminal.