Rapid supplemental heat

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Jan 1, 2026 | 11:56 AM

Garbageman 134

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Rapid supplemental heat

Is there a way for a Ford mobile technician to see if the rapid supplemental heating system is activating when the truck is started cold? I have the Dual alternator dual battery option

Jan 1, 2026 | 12:32 PM

Joe T

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From: Chaz

Find a way to pull up your original window sticker. I think carfax or the dealer can.

I assume this is the question, have it or not.

Jan 1, 2026 | 01:27 PM

Ltngdrvr

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Quote:

Originally Posted by Garbageman 134

Is there a way for a Ford mobile technician to see if the rapid supplemental heating system is activating when the truck is started cold? I have the Dual alternator dual battery option

Dual alts is part of the supplemental heater package.
Has to be cold enough before the supplemental heat activates, I don't recall what the temp threshold is.
But, if that condition is met, then a tech with a IDS scan tool should be able to see it.

Jan 1, 2026 | 02:01 PM

Flatland1

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Turn your temp selector to high...........it won't come on if it isn't

Jan 1, 2026 | 03:57 PM

Ltngdrvr

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Quote:

Originally Posted by Flatland1

Turn your temp selector to high...........it won't come on if it isn't

Mine comes on without temp set to high or max or whatever, so long as it is very cold out.

Jan 2, 2026 | 12:58 AM

Garbageman 134

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Quote:

Originally Posted by Flatland1

Turn your temp selector to high...........it won't come on if it isn't

14F and temp set to HI.

Jan 2, 2026 | 05:06 AM

Joe T

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From: Chaz

It isnt very strong. Just luke warm, enough to cut the cold bone chill.

Glad its in the 70s here today 😅

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Jan 4, 2026 | 02:36 PM

jimzpsd

Cargo Master

Joined: Feb 2017

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From: Wisconsin

My '17 has this feature, this morning it was -18*F, I started the truck and set the controls to activate the supplemental heater, with in three minutes I could smell it, almost like burning dust. Since day one with this truck this has always been my indicator telling me its on. Works good too.

Jan 5, 2026 | 06:08 AM

#10

99powerstrokedF250

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Quote:

Originally Posted by Garbageman 134

14F and temp set to HI.

This right here is what it says in my manual. And it works...for the most part. It's probably only putting out 80° or so tops, which with a decent fan speed doesn't even really feel warm...just warmer than outside.