01 diesel excursion. Batterys are dying. Sometimes it takes hours/sometimes they will last 2 days. Both check out ok as well as altenator. Charged them with external charger with the same results. No lights or anything running while key is turned off. Any ideas?

The light is telling you the battery is low on charge. What you need to do is check the alternator and see if it is putting out the correct amperage. If you go to Auto zone they can check this for you and I believe it is free. Another test you could do is start the car and pull the positive cable from the battery and if the car dies then you have a charging problem and most likely is the alternator. A couple things about the battery itself. Make sure the connections are clean and tight. If the alternator is good then maybe the battery is not taking the charge from the alternator.

sorry I can't give you a hard fast answer because I am having 38C days and can wear T shirt 12 months of the year, but check your thermostat first, if stuck open it will never get hot, check for blockages in the heater hoses and lastly, your tap operation

on diesels this is comon on the escort diaphram in lift pump splits letting air into main fuel line allowing fuel to flow back to the tank no sucktion no fuel

go see a mechanic my friend..

check belt @ tensioner to make sure a/c belt is in place @working,, are you sure all wires are connected to altenator ? bad battery possible.. autozone can tell,,hope this helps!!!

I have had the exact problem. I've changed altenator 3 times also and it has the same leak, but I've changed altenator an batterys over 2 year span. It just happend to me today after not driving it for 5 months. It's been in storage while I was away. Drive it fine for 2 days but today the radio kept shutting off and finally the car died right in the middle of the road. Bought a new battery because I had a warranty on last battery, but bought it just to get it home and in the driveway. Did you ever find out what was wrong with it?

It seems the starter is playing up.First check if your battery is charged fully or try to jump start and see what happens.If the engine start then it's either you need a new battery or else you need a replacement alternator.Test using a voltmeter if the actual altenator is working.Finally the last option is the starter motor that needs changing or fixing...Hope this helps.

Altenator not charging.Start the truck up and pull the possitive cable off the battery and if it stay's running then the altenator is working right but if the engine quits the altenator is no good

a 7.3 with 97K miles is just getting started on it's lifespan. These motors will last for sometimes 300K miles with regular service. They do have a 100K powertrain warranty so you're close to out of warranty on this one. The transmissions and torque converters were sometimes weak, but if you treat them right, they'll last.
Personally, I've got a ;'01 Limited since 2003 and I've got close to 180,000 miles on it... I've done regular service on it, brakes, changed the tranny out, have a banks kit on it, and it runs like there's no tomorrow.
Great rig, highly recommend a diesel.
Even tho ford isn't making the Excursion any more, the Super Duty is around to stay for a while so there'll always be service parts for the Excursion...
Hope that helps in your decision... KEN

shoted battery check the battery disconnect cable and take booster cable check if its ok HOPE IT HELP FIXYA OUR POST THANKS PIERRE