Hey all,

Im really pulling my hair out over a recent electrical issue my Explorer has developed. It happened randomly a couple of times when I first got it, but recently, it happens a TON. Here is the conditions.

Upon turning on, several things will not function. The driver window will not go up or down, however all other windows work from the driver switch. The sun roof will not function in either tilt or open. And the compass in the instrument cluster display will show two dashes "--". Sometimes after I drive a bit, Ill see the compass display direction, at which point the driver window and sunroof will work perfect.

It never seems to drop out while driving. It is either malfunctioning on start up, or works perfectly fine. But it will fix itself while driving. Sometimes after a few seconds...sometimes 45 minutes +.

Things Ive tried... I pulled the circuit breaker (CB1)...that kills all windows. I have unplugged the driver switch panel, but everything else still works. The only other thing that I can tie these items together, is with the accessory delay relay. But I cant seem to even find that.

Wiring diagrams dont really show a place that could be broken, that would only affect those three items. The only other thing that seems to be wonky right now, is the memory seats. My #1 setting works, but my wife's #2 is gone, and we cant get it to save.

Any ideas? Im all ears here.

Justin

 

While looking at the wiring diagrams, did you look to see if the ground was shared for those items? When weird electrical things start happening, I clean grounds no matter what they may look like. I would clean battery terminals, too, even if they look clean on the outside. With the battery terminals off, you also get the benefit of a cold reboot, which has cured odd behavior on my most modern vehicle on several occasions.

How is your battery voltage?

 

Thanks for the reply.

I did check the ground schematic. I cant see any shared grounds that all three have in common. Its really weird.

Battery terminals are super clean, voltage is perfect, and everything else works 100%. The only things that have been "modified" are a Viper alarm with remote start, and I have a tablet/aftermarket radio installed. But that is all plug and play, and I dont know why that would affect the systems that are failing.

I might try a cold boot, but I know for a fact it did it a few times, then the battery was disconnected for almost a month while it was at Ford being worked on. So if it did make a difference, it was short term.

Im convinced its either a break in a wire, perhaps there is a power leg that they share, or its a fault in some module that I wont be able to diagnose. The accessory/delay relay is trigged by something in the diagrams called 'CONTROL'. Im assuming that is the PCM, but I havent tracked it down yet. Ide still like to find that relay. Its labeled "ACC/DELAY RELAY" and its shown as a standard relay. Just cant seem to locate it. Owners manual just says its in the passenger compartment.

Justin

EDIT: Just went over the diagrams again. You might be on to something. Both the driver window and the sunroof share a common ground near the driver kick panel area. Im wondering if they maybe used that ground for some of the alarm components.... Of course I didnt drive it today, so Ill have to look later. If that turns out to be something...I owe ya a beer.

 

I know you mention the battery terminals are clean and the voltage is okay, but how old is the battery? If it's more than 3 years old, it's about due to be replaced anyway and before getting too excited about wiring issues, I'd suggest either a new battery or try putting the battery on a charger overnight while the vehicle is not in use, then either determine the issues still exists or after a week or so conclude that battery voltage plays a role.

So many strange and seemingly improbable electrical issues in modern vehicles have been traced back to weak battery issues, even when the battery seems to test fine using "old" test methods.

-Rod

 

I agree that battery health plays a big role in lots of issues.

However, this battery is 100% healthy. Its only a couple years old...3-4 tops, and its a quality battery. It has zero issues starting the vehicle, running lights, running the radio while the car is off, etc etc. I would certainly think other systems would show signs of issues at the same time.

The malfunction is so specific, affecting such a strange group of functions, there has to be something else going on. Everything else functions 100%. All displays, all windows (even while driver window doesnt), all lights. Something is tying the driver window, sun roof, and compass display together.

Im now convinced that it has to be a fault in one of the "convenience modules". Today I pulled the ground wire for those functions, and it didnt cause the compass to blank out. It also shut down more than just those three areas, so I think the ground is ok. Everything is really clean, and undisturbed.

I was able to get the malfunction to manifest itself, and while it was, I tapped around on the interior fuse block, where the CB1 circuit breaker is, and it came back on. So I need to take some more time and poke around up there to see if anything is disturbed due to alarm install, or if I can maybe find the mysterious accessory delay relay.

J.

 

So just to keep this updated since I bothered to make a thread...dont want to leave it to die.

All day yesterday the issue was present. Several trips...window,sunroof and compass inoperable.

This morning it started out that way. Upon using my foot to tap around the fuse block inside the car, it suddenly went away. Then...it came back. Tapped again, it went away...then it came back but took a little longer. While going through a drive thru, my wheel hit its lock...and the problem came back. Once again some tapping made it go away.

There is obviously something mechanically wrong down in that area. Now...behind that fuse block, is some sort of module. Im wondering if this houses the "accesory" delay relay. I dont think my tapping has anything to do with the actual fuses, because more systems share fuses than are malfunctioning. In other words, if a fuse controlling the windows was out...all of them would be out.

What I need to do is remove that fuse panel and get to the large connections behind it. I also see what appears to be a standard bosch sized relay in the side, but its not accessible. Which makes sense, because in the manual it says to see your dealer for fixing this.

Lastly...since cold seems to have a serious effect on the issue, Im really convinced its one of two things. Its either a) an actual relay and the cold is making it lethargic/stick worse. or b) its a busted solder joint that once it warms up it expands enough to complete the circuit....or upon being kicked haha.

Has anyone removed that inner fuse block? Can you clue me into what I might find?

Justin

 

It looks like I have a service manual for the 2010 model year. I haven't checked to see if it covers the Explorer, and that will take more time than I have this morning. But, if you send me a Private Message with the request and an e-mail address for you, I'll pull up what I can on the passenger compartment fuse/relay panel and send it your way as a PDF.

-Rod

 

Here is a picture.

One Ford parts salesman called it the "smart junction box". The parts sites call it the anti-theft control module. I dont think its only for anti-theft...since there are so many other circuits fused in it. Smart junction box sounds more appropriate.

Here is a pic. You can see the relay on the side. I believe this might be the acc/delay relay that is mentioned in the owners manual. And probably why they say see your dealer to service. I think the box has to come down to access it.

I am going to replace that relay i think. While I have it apart, Im going to clean all the connectors that go into that box. There are 2-3 big, latching connectors that go on the side. Ill clean them up and make sure all connections are good.



What I really want to do, is catch it failing again, then just use a screw driver and lighty tap on JUST the relay. If the problem goes away, Im fairly certain this is my issue. Sucker is sticking. If it doesnt, and I smack the whole box and it goes away, then I think its a connection problem.

Justin

 

The SJB diagrams are on the way to your inbox. Per the factory service manual, the relay shown above is the rear defrost relay.

-Rod

 

Shorod...THANKS!!! I got them, and they will definitely help.

I was prepared to disagree about the rear defroster relay...but when I turned it on, its def clicking. So it looks like thats correct. Upon looking at your files, it looks like there are several replaceable relays on the SJB. I couldnt quite see up there, so there could be two in a row, one hiding the other. I need the weather to break so I can take it apart.

Its still a mystery as to where the accessory/delay relay is, IF its not actually mounted on the SJB below the defrost relay. Most of the relays in the smart junction box are marked as "not serviceable". The acc/delay is not, its show as a standard relay.

Yesterday morning, lightly kicking or tapping the SJB didnt make the issue go away like the day before. SO I started to push up on the fuses and wiggling the box. When I got to the end nearest the rear of the vehicle, the problem went away.

After that, Im pretty convinced that there is a connection issue. Either the internal circuitry of the box is faulty, or one of those connectors just needs cleaned up. Ill have to dig in. If its the internals of the SJB, Im not sure I can fix it. Those things are $240 which is a bummer.

I have a theory... its right near the e-brake pedal. When you really mash the ebrake, then release it, it creates quite an impact in that area. And its right by the SJB. Im wondering if it caused a busted solder joint, or some other issue.

J.

 

Once you get it removed and apart, if you see something like a bad solder joint or an electrolytic capacitor that is leaking, send me a photo of the issue. I have some experience fixing automotive ECUs for similar issues in the past.

-Rod

 

Absolutely. I dont have an issue touching up solder joints. If there is anything beyond that though, I might be a little stuck.

After looking at it some more, it looks like I do only have one relay. In fact, the spot that is for the accessory delay relay is blank. But what I did notice, is that the fuse holder portion of the SJB is just snapped onto the main body of the whole unit. And I can see a circuit board behind there. I can only imagine there are quite a few spots for a physical connection issue.

Removing the SJB doesnt look too bad, but I think the ebrake/hood release assemblies might have to be moved. I have to look further. Hopefully removing the SJB, then reinstalling it wont screw up any of the coding that the dealer has to do. I think thats only if you are instlaling a new one. Fingers crossed...

Justin

 

So, Just to update this.

Its been two weeks, a couple of really cold mornings, and lots of miles. The issue has not come back. Not only has the issue not come back, but my memory seats are now working again.

I never bothered to take the SJB apart, because it was working fine. When I pushed up on the SJB, I swear I heard a "click" noise. Like something snapped in that wasnt fully snapped in.

The fuse side of the SJB looks like its clipped on to the main body of the box with little clips. Im wondering if the e-brake slamming into the up position caused some of them to pop loose. Its a pretty violent slam when you release the brake. Maybe it caused a shotty connection. The area of the SJB fuse panel that I pushed on and clicked, actually corresponds to some of the functions that were failing. So the sunroof, memory seats, etc. Another reason I feel that its probably fixed.

Either way Ill leave it alone and see if the problem crops back up.

Justin

 

Wow, that would be great if this keeps working for you!

Thank you for following up!

-Rod