These are common for the pump shaft splines stripping in the torque converter. The transmission will need to be removed to fix it. Before you condemn the trans, does the speedo move and the van doesn't or do you hear any grinding when you put it back into park? Or can you push the van in park (Broken CV shafts)?
First,open the hood and at the back left (your left) you will see a large wire harness attached to a computer.Remove the computer connections and clean them with "contact clean".Reinstall the connections and waterproof this area,as Ford did not and these connections are famous for corrosion.Chances are now your Windstar will run better than ever now.
Moving only one way is usually the sign of a bad switch or a wiring issue, not the regulator/motor. It's usually the master switch that goes bad since it's used most often. You can't bypass it because the power and ground both run through it.
Are your spark plugs and plug wires in good condition. I had an older Ford that did that and I found the spark plugs were not in good shape. We put new plugs and changed the plug wires and bingo the car ran good after that. Just a thought.
Buster, check the transmission fluid level, if level OK it is something wrong internal of transmission,torque converter,pump,shaft splines stripped,etc. Take into a good shop for diagnosis and estimate to repair/replace.Check the attached links,instruction and guides, Good luck
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Wiring diagrams are published in auto repair manuals. You can buy one from Ford for big bucks or buy manuals at auto repair stores and book stores or many libraries have them in the reference section. Usually they won't let you check them out but you can find what you want. Here is Chilton Online. I haven't used them and It's my guess is that you have to pay for downloads. Chilton Auto Repair Manual Online
Hi just a falt,cant you get a studd remover on the part thats left or mole grips,I know this is not what you asked,just falt it might help,
I wish you the best,always the little things that try are paesiants.
sorry about spelling.
Usually kept in several places. One is in owners manual, another is behind storage doors (small doors in cargo area with jack and rear washer storage) or on back of spare tire area in back compartment. Look for a sticker on back side of spare tire cover, or in front or rear of owners manual etc. It sometimes is just a sticker with 5 numbers on it and says nothing else. If all else fails you can usually have dealer look it up if you bring paper to them showing you own vehicle. The manual tells you how to add your own number to also work with system - but if battery unhooked for long enough it will go back to just remembering factory code.
Make sure battery is strong and try leaving key in on position for 5 to 15 minutes. Then go to start. This works on many vehicles - but many are different. If chip key and theft module working leaving key on for several minutes is supposed to be long enough to tell system vehicle is not being stolen (not many thieves willing to sit in car waiting for 10 minutes). If chip key or key "reader" has failed you need dealer help.