I want to bring back an old thread since I'm having similar problems. It's going to be long and painful read but I'm hoping someone can help stop the bleeding.
--- 2004 Ford Explorer Eddie Bauer V6, 145,000 ---
I purchased this vehicle brand new from Ford and it's been the most costly vehicle I've ever owned. Here is a list of the parts I've replaced -- Transmission, rear end, rear axle and rear axle seal on the other side, rear air control unit [2 times], sun visors, harmonic balancer, thermostat housing, alternator, battery [2 times], a/c fresh/recycle air door [don't know the exact name]. Obviously, a few of these things you expect along with tires, brakes, etc.
A few months ago as my wife was driving and thought she may have hit something because of the way the vehicle shuddered. It was hard to tell by the description alone until I was able experience it myself. While in motion the vehicle lost power and regained power all within an instant and shudders the vehicle. The vehicle has done this several times since. Also during this time the vehicle has stalled on several occasions when pulling up to a stop sign, light, etc. I did a bunch of searching on the internet and thought maybe it was a computer problem of some sort. Ironically, it's very difficult to find a company to refurbish this model ECM for some reason. Other information suggested TPS or Throttle Body problems. I made my way to the local Ford dealer and happened to run into a super nice mechanic as I was walking up.
He had a computer in hand and put it on the vehicle and of course no error codes were reported. I filled him in on the issues that we are having and he suggested that maybe it's a bad Throttle Body. After looking at it closer he said these are problems on this engine with the Throttle Body and suggested having it replaced. In the mean time he took my vehicle back and cleaned out the Throttle Body and said that it may help for a short time. It was about a month and we started having issues of stalling again. This time however, the wrench light and engine fail safe mode showed. I took it back to the dealer for an official diagnosis and the computer didn't register any error codes, go figure. Either way the same mechanic ended up with the vehicle and $600 later I have a new Throttle Body as of yesterday.
Yesterday evening, two hours after bringing the vehicle home it stalled again. What seems to be ironic is that each time that we have had these problems it's been raining heavily for a few days.
Which leads me to this fun fact to add to the mix. We have the auto headlight function which may or may not matter but I'm putting it out here for information. For whatever reason the light switch was turned to the off position one evening. The next morning I was getting into the vehicle head off to the airport and by habit decided to turn the headlights on. The motor idled down a 100-200 rpms and ran rough. I turned off the lights and the motor ran well. I turned the switch on/off several times and noticed the same thing happened each time so I just headed out without the lights and it ran fine. I called a local mechanic to explain some of the symptoms and he immediately mentioned that it's possibly an alternator problem. It can't be, I just replaced the alternator with a new one after trying two bad rebuilds. The battery is also only six months old. The mechanic suggested that the alternator was not charging the battery properly and was possibly drained enough to cause a problem. So, I went to the local Advanced and had the two tested since that's where I purchased the alternator. At the end of the test the report showed that during the start up the battery didn't have enough cranking power and they suggested a charge. I let the battery charge for 30 mins ran the test again and it appeared to have corrected the issue.
Well this problem is back. It's been raining for two days and dark this morning so I obviously needed the lights. The truck ran terrible to work this morning for me stalling, or trying to stall/cut-out several times during the entire trip. I stopped for gas and decided to drive the rest of the short distance without lights. As I've noticed previously, it runs fine without the lights. So, I believe that I may have worked through one issue but now I have to work through an even more difficult and costly issue. Electrical.
Does anyone have a good place that I can buy electrical diagrams for the vehicle and service manual?
If anyone has thoughts, ideas, or opinions I would be glad to listen.