Hello!

I've had an ongoing problem with my 2006 ranger sport, 4.0, 4x4.

The radio won't power down after removing the key. This is intermittent, sometimes it will shut all the way down, but I am not sure the reasons. I can hit the power button on the radio to at least kill the playback, but the display remains lit up with the clock well past the auto shut off time. It actually stays on days at a time.

The dome lights work normal with open/closed doors on both sides. power windows will not work with the ignition off. The chime that goes off when the door is opened and the key is still in ignition rarely works these days.

I had the battery tested, it tested bad even though the truck started perfectly every time. So I replaced it a couple of months ago and it seemed to be working fine, then it started up again. It did seem like it started acting up again with the start of the wet season here..

Older symptoms that haven't returned are with the power locks. They would sometimes automatically lock again after hitting the unlock button, or maybe it was the reverse.

I've read possible problems to be the Ignition switch, GEM module, a faulty relay, the radio itself, a short, or a short caused by moisture seeping in around windshield.

With these symptoms I was hoping for guidance on the best place to start. I want to keep costs down as much as possible.

Thanks!

 

Well '04 and up Rangers should have a Smart Junction Box(SJB) this replaced the GEM I believe, located behind the passenger side kick panel.

There is a system that keeps the power windows and radio on after key is off, that part is normal, but radio and window power should go off when Drivers door is opened(assuming key is still off)

You say the power to the windows does go off, and I assume the "Door Ajar" light works when drivers door is open, then that means the drivers door latch switch is working, so not the problem.

But another issue is that '06 will also have a Battery Saver relay, this is on a timer, timer starts when key is switched off, then after 20-30 min. the relay will open and cut power to most of the systems in the truck, so if you were to leave the lights on or radio on power should be cut automatically after 20-30min.

I would google: ranger smart junction box
And see if any of the stuff matches your symptoms

 

Did you found something about your problem.
The same thing happened to me today. When i tried to start my pickup this morning the battery was totally drained. I reallized that the radio stayed on all night and now it wont turn off. I need to unplug the battery to be sur that is stay off. Event removing the accessories fuse wont turn it off (did you tried it?).
On mine (b4000 2011) the radio should turn off when a stop the ignition, there is no system that let it countinue until the door is opened (dont know for you)
Don't know if this is the same trouble, but if you found something could you post your solution.
Thank you

 

Well, I looked into the SJB and haven't found anything conclusive.

Today I swapped out the ignition lock cylinder and it shut down the first couple of times i turned the truck on and off. The key in chime is working again now.

Then it started to stay on again. I then found all the ground lugs I could under the hood and hit all but one of them with a wire brush. I didn't have a long socket for the last lug. I also cleaned the ground next to the SJB. The radio is turning off every time now so far.

I have now noticed that the radio will come on when the headlights are switched on even if the key is out. I don't think this is normal, but still an improvement over always on.

I did not crawl under the truck to look for grounding lugs, Should I?

What would make the radio come on with the headlights now? It may have done it before but never noticed it.

 

The lights in the radio get power when light switch is turned on, could be a short in the radio or SJB

Go here: Ford Ranger Radio Wiring Diagram
Go down to the last 2006 wiring diagram

You will see the 3 power connections and a 4th that says illumination #1

 

The SJB suffered from water leaks that cause all kinds of problems.

 

I have some new updates, now that I am back to working on it. There was significant water buildup in the tail lights so I removed and dried them, the bulb sockets seemed ok, (note that I am not skilled in this evaluation).

I found that the tail light wiring harness connector, C421, that connects to the harness running up the frame, was suspended right at the gap between the end of the bed and the bumper. That means any water draining from the bed will poor right over it. I got it apart and it seemed ok to me again. There was still a significant amount of grease on the pins still.

I pulled the drivers power lock switch out and found significant corrosion on the exposed copper on the bottom of it. I can only assume that there is more inside it out of sight. Is it possible to disassemble? I have seen replacements for about 40-50 bucks online. Is there a cheaper source for them?

I am replacing the accessory relay today on the SJB. After studying the wiring diagrams, and other research, I saw how that it can cause problems if bad.

I have checked many times through the wet season and cannot find evidence of moisture getting to the SJB.

I did however find Significant corrosion on ground G205, under the drivers seat.

I have a multimeter now, but the thought of actually testing the various wiring harness' is quite daunting.

My rookie estimation as it is now is that if there are still symptoms in the future, I would think that the problem is the radio itself, the SJB, or fault in a wiring harness. If symptoms do recur, I will pull the radio fuse to see if they go away.

Update:
Accessory relay replaced. Radio still powers on when lights are turned on. I don't know if it will still keep coming on randomly with the truck shut off yet. My CFO & wife has given me the green light to replace the radio. She wants an aux/BT input anyway. I suspect that the random triggering of power locks may have been a separate problem from the radio.

 

I seem to have solved it. I put a new stereo in a couple of months ago and have not had a single problem. I am very glad that it was not the SJB.

 

i drove an 03 explorer with 318k and it wouldn't shut off. The headlights flashed like crazy too and people kept pulling over haha