My SUV started running rough, around a month ago. It seemed to me that there might be a problem with the transmission, but I went to the repair shop and they said the engine is the problem. Some spark plugs were replaced and some other things, not sure what. They also serviced the transmission, even though they said it was fine - and then it ran great. Before this service call, at a different auto repair shop, I had gotten a lube job, had the oil changed and replaced the air filter. I had also had the mirror replaced on the driver’s side. This morning, coming home from a long trip, every time I would put the SUV in Drive, it would die. On the gear shifter, the overdrive indicator was flashing. I read the manual and it said that means that it needs immediate servicing. Yesterday, for the first time, we started having intermittent difficulties with the electric windows not working properly. Do you think any of these problems are related and what should I do?
You may want to have faults surveyed to see if there are any underlying issues on your 2003 Ford Excursion. Battery voltage is extremely vital to vehicles with heavy electrical systems such as the Excursion. If the battery voltage drops low nearing the 10v mark, computer and electrical system malfunctions can occur as a result with a whole host of various seeming non interrelated malfunctions occurring.
The charging system should be looked at as well to ensure you are not getting the opposite effect of overcharging where a system voltage that is too high can cause malfunctions and ultimately damage as well.
Now there is a bulletin out by Ford concerning 2002-2005 Excursions developing corrosion on the blot of the positive terminal. This can cause contact issues, which could lead to various electrical system malfunctions.
There is a repair kit available that will avoid replacing the engine positive battery cable which is a very costly and involved repair. You may want to enlist the help of a mechanic, such as one from YourMechanic, who will have the tools, training, and expertise to diagnose and correct your electrical system issues.