You can google this stuff up....I did....
DC amp output is dependent on the alternator, but seems to be around 35-45 depending on equipment.
Fuel is the same but appears to be around 1/2 gallon per hour at idle.
Don't think you got an earlier answer as most likely no one has a need to let their truck idle for an hour, either for fuel or amp measurement.
Groo since you're the only person interested in this idle fuel consumption issue for going on 3 years now, I'd recommend you perform a non-scientific test, but a test nonetheless. And you can share your results back with us.
Fill you truck 100% and then pull forward and park in gas station lot parking spot and let your truck idle for 1 hour, read a book, fill the truck back up and see how much gas went in. Amount filled on the second fill up would be roughly how much was burn from the full tank after 1 hour of idling in the parking lot. I think that's going to be the closest / best method you could come up with to get a rough estimate on the fuel burn at idle.
As for your Alternator question - unless a person knowledgeable comes up that knows alternators inside and out I could only spit back the same answer you'd get when you google "What is the output of a Ford Ranger alternator." (It says it's stamped on the side of the unit.)
The alternator amperage is going to vary, depending on what the battery voltage is and also any load draws, lighting-HVAC, blower motor speed, radio on etc.
You can view this with scanner or Forscan
The Fuel Burn, this can also be viewed with a scanner or Forscan in a digital reading of the fuel level
in gallons.
I believe this can also be viewed in the Engineering Test Mode Screen on the IPC
So, record current digital fuel level number and let it idle for 30 mins, record reading and subtract from starting reading (?) (x2) to get per hour fuel burn @ idle.
I checked the engineering screen , it’s not on it. But I know it is an available PID for a scan tool , it will be fuel tank level in a digital readout in gallons
On a scan tool fuel level is read as a percent (0-100%), if in the Ford specific tab is reads 2 digits.
If you use the Global OBD2 tab it will break it down to 3 digits (63.2%)
So, you would have to do some math (goes -intas) to get an estimated fuel burn per hour.
Now, I found this IPC (Forsacn) change that may or may not work on the Ranger
Enable: Fuel Consumption (Per Hour) Display
IPC: 720-02-01
xDxx-xxxx-xxxx - Factory Disabled
xFxx-xxxx-xxxx - To Enable
This is untested, so I do not know if it will work.
Necroposting, but for future reference to other people interested. The alternator outputs a minimum of 105 amps at 750 rpms (idle) and 170 amps max at 2,250 rpms, so there should be plenty of available power to tap into even at idle.
Thanks airline tech for the loads, much appreciated!