I Have a 2004 ford expedition. 5.4 engine. This has a heavy duty towing package. I just had a towing braking system installed. I tow a camper from time to time which is 8000lb. I think my altenator just went bad. My engine warning was saying check charging system. I recharged the battery and the car started again but it wears down quickly. I called a ford dealer and they seem to think I need a new altenator. They suggested replacing my 110 amp altenator with a 135 amp heavy duty altenator because I tow the camper and they said I could use the extra amps. Is this a good idea? The heavy duty altenator is twice the price as a 110 amp altenator.