Hello I have a 2014 fiesta st180 where the other week my air bag light came on. I didn't think much of it, so I tried disconnecting the battery, and it went away for a day then came back. A few days down the line, my windows all of a sudden stopped working and started again. Then I parked up at my house and saw the battery light came on and the car ran rough. I turned it off and then the car wouldn't start again so I put some testers on the battery and saw 10v so the alternator wasn't charging the battery so i trickle charged the battery and drove it to ford(only because I have extended warrenty). They diagnosed it as a alternator, fitted it, it wasn't that, then said it was an "alternator module"(not even sure if that's a thing) they fitted that and said that the cars charging the battery now and will start but that the air con, air bag light is still on and the windows don't work so now were 9 days down the line and they don't know what it is they've just said it's a wiring problem which doesn't make sense to me because it was all down to the low battery voltage personally. Anyone have any idea please and thank you.

So we got to the end of the problem after 2 and a half weeks in the garage, they've said it was the start button causing all this problem(also the alternator I think) so a new one wad put in. Ty Ford warrety this was all free again

Hi Brandon

I have been trying to repair the same fault on a friend of mines car. Airbag light, windows not working and heater/ac not working. 

So you say that ford replaced the start button and this resolved the faults? 

I did see that you had posted on that other thread where they were experiencing the same problems but no one had come back with a solution.

I do have the fault code U300f-ignition input accessory and u0423-invalid data from IPC in the abs, drivers door module, passenger door module and restraint control module, this all being very similar to that previous thread. 

Was thinking it could be a faulty IPC but having tried with a doner one fitted (although not programed) the windows still don't work but they do with the IPC disconnected. 

Looks like trying a replacement start button is worth a try!

I have the same problem for 3 years now with my for mondeo, the dealer also said we have to change all wires in the car, that will cost me like 3000€, and than maybe its fixed, i already paid 1600€ for changing battery mid cinsole and bcm module but the priblem came back in 3 days

2 hours ago, Murkus said:

the dealer also said we have to change all wires in the car, that will cost me like 3000€, and than maybe its fixed,

Perhaps you need to find a dealer that knows what they are doing and how to properly use diagnostic equipment including a multimeter. I'd just walk away from the dealer and find a good auto electrician (NOT a mechanic). Even if it took two days to find the fault it would be cheaper.

Solved( i hope) 

Well i have found in ford fusion owners club a topic that have solved my problem, it have to do with canbus comunication, this wires if they have moister they dont comunicate well and can shut off parts of the car, so some corroded wires under the right hand seat, y cleaned cables and sockets and everyting is working for the moment

https://www.fordfusionforum.com/index.php?app=forums&module=forums&controller=topic&id=21307&page=2#comment-121675