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Electrical problems on 2007 Ford Explorer

I have a 2007 Ford Explorer that died on me earlier. When I was driving yesterday, I had maybe gone 2-3 miles when everything in the car died (headlights, dash lights and gauges, interior lights, windows, door locks) except for the (aftermarket) radio head unit. The car was still running when this happened but when I pressed the accelerator, it was revving high but not shifting, however as soon as the revs went up (not redline), everything in the car flicked back on and it continued driving for a little while after with no issues.

This morning, I went out to grab my girlfriend some coffee creamer and about a block away, the same thing happened again and I pulled over and the car cut off. When I tried to start it, I got nothing but the slow “click click click” that happens when the battery dies and is dead. Signs pointed to a completely dead battery as nothing was working, however the radio still was powering up without problem (my guess is because it’s wired in differently because it’s aftermarket) and when the ignition was in the “on” position, all of the lights and systems started rapidly pulsing and the car made an effort to start but didn’t turn all the way over and everything went dead again.

I do not have a lot of experience working on cars but I’ve always had an easy time understanding machines. Generally reading up on a particular car system or looking at blueprints has helped me to figure out things in the past. I’ve been reading up on what I can today (dealing with a newborn however) but figured some direct advice may be best for this particular problem.

My slightly educated guess is that there is an issue with the ground circuit, the battery terminals, or ignition switch. I’m not thinking it’s the alternator because of the working radio and the fact the car started with no issues and suddenly cut off power. Maybe a bad battery but then why would all of the systems be dead but the radio still coming on without problem?

Just for possible help, the truck has had some computer issues where the ABS, Drivetrain, and another light I don’t know go on and off intermittently while driving and sometimes the engine light comes on for a couple days and goes off for awhile (months usually). The code given by the engine light says it’s a problem with a control module and I’ve read of other Explorer owners having similar issues.

Any ideas would be appreciated. I don’t know if it can be avoided but I’d like to do whatever I can before paying to get it repaired. I can borrow tools and have a voltage meter.

What is the battery terminal voltage at rest and when attempting to crank?

The problem might be caused by a Body Control Module starting to fail.


Apologies, been busy but got a chance to take a more deeper look at the truck. The battery was totally dead when I went back to it (not even the radio or the ignition lock was working). I took apart the terminals and cleaned them along with rewiring the one. After that, I got someone to give me a jump and it started right up from a jump box but everything cut off as soon as we removed the cable. Had someone look at it with me today and we used the voltage meter. The battery was at only one volt. We got another jump and ran it off a jump box (it still didn’t have enough juice to start after a couple minutes on the box) and another vehicle battery for a few minutes. When we removed the cable connected to the other vehicle, the voltage started dropping. After shutting it down and removing all the cables, the battery was sitting at around 4 volts after being between 12 to 14 when hooked up.

The guy who helped me look at it said it was 100% the alternator and offered to replace it himself for about $200 (parts included). I’m still concerned it could be something else however. The wire to the alternator had juice when we checked as it was running. I wouldn’t think the alternator being bad would result in a sudden and total loss of power to everything in the vehicle, I figured it would be more something like gradual weakening of power or not starting after it’s been running. Could I perhaps be looking at two separate problems? The wiring to the positive terminal was god awful and at a first glance, the mechanic from the shop up the street said immediately that it was a connection issue. Coincidence that it could’ve been causing a problem in addition to the alternator failing? I’m obviously no expert on this but could a bad battery also be the culprit if it’s not holding a charge?

If you ask me the battery is toast. And asking your alternator to charge a completely dead battery and run the vehicle is going to kill the alternator too. First step is to attempt to trickle charge the battery with an external battery charger. If it takes a charge, and that’s a big IF, then start the engine and measure the terminal voltage. If it’s closer to 14V+, nothing wrong with your alternator, save that money.

That was what I was thinking. Either way, dead alternator or not, I’m sure it’s going to need a new battery. Should I just go buy one and put it in and measure the voltage after I start it to see if it’s dropping? I know a bad alternator can kill a battery but not immediately.

Another question…if I was able to borrow the needed tools, would replacing an alternator be something I could do on my own (if it comes to that)? I’ve done work on cars in the past using guides and the like. I was an engineering major in college and have helped with electrical work and various machine repairs in the past so understanding things is generally not too difficult for me but I do not want to wind up over my head with a vehicle in pieces.

The battery is probably dead, given the number of times you found it discharged. Possibly, there is a short in the system somewhere draining it, but at this point it is probably dead anyway.

do as TwinTurbo suggests, get a new battery and see what happens.

I was thinking of a short as well but I didn’t find any signs of one and all the components were working fine while still hooked up to another battery/jump box. Still a lot of wiring that could be checked however but a short circuit likely would’ve fried some things, wouldn’t it? I’m crossing my fingers that it’s just the battery because it’s been rough financially lately with a new baby and all and the truck needs other work done on it as well. Hoping to get a new vehicle soon but don’t know if I’ll be able to swing that before more issues arise.

Thanks for the help to everyone btw. I prefer to try and learn these things myself instead of relying on others to do the work. The upside of having car problems is it ends up being a chance for me to learn new things.

I just wanted to come back and report my resolution in case anyone was curious or it can be helpful to somebody else in the future.

I ended up getting a really good deal on both a battery and an alternator. A friend of ours is a manager at a parts warehouse and got both for $164 total so I decided to just go ahead on both before I had properly diagnosed the alternator. I put the new battery in and was able to get it started and back to the house (it was on the road down the street). When I checked the battery with the voltage meter, the voltage was not increasing while the engine was running and was sitting at around 12.25 volts and 12.4 when off. Went ahead and replaced the alternator myself (which was very easy to do with the proper tools) and got good readings from the battery after. There was also a slight whining sound before I changed the alternator that went away; I don’t know if that was necessarily indicative about it’s status but figured it may have been after the fact.

Anyways, thanks for the assistance everyone. While I still ended up having to repair and put some money into the truck, I enjoyed the experience of getting to learn some new things. Perhaps I’ll hang around here on the forums. Anyways, thanks again folks.

Nice work - and thanks for getting back here to report your success.

Glad you are back on the road with a reliable runner. Good for you. Thanks for posting the resolution to the problem.