Upfitter Switch as Ignition Switch/Relay??

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Nov 13, 2010 | 11:44 AM

#16

Zmann

Posting Guru

Joined: Oct 2009

Posts: 2,453

Likes: 4

From: AZ

Quote:

Originally Posted by senix

disable the starter and a separate disable for the fuel. That is what you want to do.

probably ok on the o8 to kill the fuel but 03-07 the injectors don't like to be dry so the starter relay signal is the best IMHO
even then I don't know what wire Sandyc because without some research you may throw a code ?

Nov 13, 2010 | 03:10 PM

#17

TexasRebel

Cargo Master

Joined: Jun 2008

Posts: 2,752

Likes: 5

From: Stillwater, OK

Quote:

depending on the year, the GEM, HEC, 4WD Control, ABS, VSM, SJB, etc, etc. They're all connected by one or more data busses, so they work together. But they are separate modules.

yep, after 2008, almost everything you've listed here is contained in the Programmable Control Module (PCM). The GEM is extinct, and the SJB houses most of the modules. The ACU has its own logical inputs (redundant audio controls).

The easiest way to demonstrate this is to pay attention on a 2008+, when you turn the headlight switch from off to headlamps, there is a noticeable short delay in the lights coming on. The delay is caused by the clock speed of the processor in the PCM.

Nov 15, 2010 | 02:53 AM

#18

GregsSD

Posting Guru

Joined: Dec 2006

Posts: 1,391

Likes: 1

From: NorCal

Here is a thread with info about converting the upfitter switches to "always hot" rather than only hot with the ignition on, it's just a matter of removing a relay and adding a jumper wire between two of the sockets where the relay was:

https://www.ford-trucks.com/forums/6...-switches.html