I'm confused about a few of the options on my F350
 

I'm wondering first about the 'Dual Extra Heavy Duty Alternators' option. Does this help me with my fifth wheel? Like, running my 1000w inverter while driving, and charging my RV battery?

Next, can somebody explain what the 'Rapid Heat Supplemental Heater' is and how to use it?

Finally, the 'Engine Block Heater.' Doesn't this normally have a cord hanging out of the front grill? I've looked and can't find one.

Thanks!

https://cimg4.ibsrv.net/gimg/www.for...138e849bda.png

The dual alternators are automatically added when the rapid supplemental heater is installed I believe, the rapid heater is an electrical heater in the vents that is used when outside air temp is less then 40 I believe and the truck coolant temp is under a certain temperature I believe 120 but don't quote me on that....I have it and love it, it's great for those cold mornings when the truck just isn't warm enough yet from remote start so it gives you some warm air till you get driving and it is just automatically controlled by the truck so no settings/adjustments. The Engine Block Heater cord I believe is tucked and clipped to the top of bumper I believe I read in another thread from factory but not a 100% sure as it hasn't been that cold where I am for me to go looking for it yet...

Feel up around passenger side tow hook for block heater cord.

All 6.7 trucks come with dual alternators as standard. When supplemental cab heat is selected so is the upgraded dual heavy duty alternators.

Your dual alts would only help with the trailer charging IF you had a lot of other stuff sucking power, like a snowplow--not likely towing... You get only the same charging ability that is possible to push power thru about 20' of small gauge wiring and several connections + the tow harness. It usually ends up being just enough to keep a well-charged battery up, but really not enough to charge deeply discharged batts. This is from experience with 6 different superdutys over 16 years.
The RSH is totally automatic when the temp/truck are both cold enough.
The block heater won't be needed unless you will be spending a lot of time in really cold temps. New SDs start really easy when cold, even below zero.

Make sure and read how to use the Rapid Heat. It's not a hot heat and works best with lower fan speeds, to gently heat the truck.

For what it's worth, I believe rapid supplemental heater is always included on trucks sold to cold weather markets. At least that is what my salesperson said.. For one, all SD sold in Michigan, where I live, have them...and thus also dual alternator.

the dual alt option in the past was pretty rare and i wouldnt recommend because parts would be harder to come by and more parts to go south...since its pretty much standard now its something less to worry about. i was always 50/50 about it years ago, pluses and minuses

^^^^^^^^^^^ What he said ^^^^^^^^^^^ Mine is clipped in there . :-X22

Your wiring to the trailer is at best 12ga (more likely 14ga or smaller). At 25 foot (also estimation) 12 GA would only carry10amps. A 1000w inverter will pull almost 92amps 12v at full output. So charging an rv while towing through the 7 pin plug provides very limited amperage. Dual alternators is only for the diesels in cold climates iirc. Can you get the supplementary heater in a gas?

It's funny you say that. I purchased my truck in North Dakota. No supplemental heater, no block heater..... I mean come on.... But I do have the extra heavy duty alternator.....ughhh

My truck originated in NH. Block heater (gas truck) and the extra extra heavy duty alternator but no rapid supplemental heater. Who knows?

Supplemental heater is not available for gas units, sorry.
The block heater connector is stored above and to the right of the passenger side tow hook. The clip that holds it can be broken, so be gentle when pulling it down and putting it back.

The truck doesn't provide much juice to the RV. I ran all three of the tank heaters on the way home last month and the trailer batteries were pretty low by the time I got home. That was disappointing. :(