Which wires give constant, ignition and ground on a 2026 Ford E-Series Cutaway?
On a 2026 Ford E-Series Cutaway, take constant power from the Red wire at the trailer brake controller connector C239, behind the center of the dash, pin 8, and ground to the Black/Violet wire at the trailer brake controller connector C239, behind the center of the dash, pin 3. Meter every wire first.
Meter every wire before you tap it. Colors change with trim and build date.
OBD-II port:Lower dash, left of the steering columnBest power spot:Trailer brake connector C239System voltage:12VEngine:7.3L gas
Where do I get constant, ignition and ground on a 2026 Ford E-Series Cutaway?
Ford builds customer access connectors into every E-Series cutaway for body builders. Use them instead of tapping the truck's own wiring.
Option 1 Colors printed
Trailer brake controller connector C239
Behind the center of the dash, per Ford's connector location drawing.
Constant
Red
Trailer brake controller connector C239, behind the center of the dash, pin 8Fuse 41 battery feed, for a trailer brake controller.
Ignition
Not on this plug
Use the B-pillar C338X, pin 4This plug has no run/start pin. Pin 12 (Brown/Blue) is the brake on/off feed.
Ground
Black/Violet
Trailer brake controller connector C239, behind the center of the dash, pin 3Instrument panel ground.
Pair it with the run/start pin at the B-pillar for ignition.
Option 2 Ignition here
B-pillar customer access C338X
Ford's power plug at the B-pillar for body builders.
Constant
Pins only
B-pillar customer access C338X, pins 3 and 6Battery feeds, fuse 97 (50A) and fuse 91 (40A). Ford prints no wire colors for this plug.
Ignition
Pins only
Same plug, pin 4Run/start feed, fuse 54 (40A). Meter it: hot with the key in run only.
Ground
Pins only
Same plug, pin 1Ground at the bottom of the A-pillar. With this ground, keep the combined load on pins 3, 4 and 6 under 45A.
Ford lists pins and fuses only. Meter each pin before you use it.
From Ford's 2026 E-Series Body Builders Layout Book. Ford prints the same tables in its 2025, 2026 and 2027 books.
Where are the turn signal, reverse and light wires on a 2026 Ford E-Series Cutaway for advanced 360 multicam and video telematics installs?
Circuit
Wire color
Location and what it does
Left turnPositive +Not yet checked
Gray/Orange
B-pillar customer access connector C3359, pin 15Left rear turn lamp. The same circuit is pin 4 at the rear lighting connector.
Right turnPositive +Not yet checked
Green/Orange
B-pillar customer access connector C3359, pin 16Right turn lamp. The same circuit is pin 5 at the rear lighting connector.
Trailer brake controller connector C239, behind the center of the dash, pin 12Brake on/off feed. Rear stop/turn: left Gray/Blue (pin 6), right Violet/White (pin 7) at the rear lighting connector.
Each chip shows the main insulation color with its stripe. Source: Ford's 2026 E-Series Body Builders Layout Book.
Where are the brake, door, speed and CAN wires on a 2026 Ford E-Series Cutaway for advanced 360 multicam and video telematics installs?
Circuit
Wire color
Location and what it does
Door ajarPolarity: meter itNot yet checked
Green
B-pillar customer access connector C3359, pin 5Rear driver side door ajar, including a sliding door. Meter open and closed.
Lock / unlockPolarity: meter itNot yet checked
Gray/Brown
B-pillar customer access connector C3359, pins 13 and 12All lock (pin 13) and all unlock (pin 12). Ford prints the same color on both pins.
Engine customer access connector 12A581, engine compartment, pin 12Vehicle speed output from the PCM.
Park onlyNegative -Not yet checked
Gray/Brown
Engine customer access connector 12A581, pin 8PCM output when the transmission is in park.
CAN busNot foundNot yet checked
Not found
Not foundNot part of Ford's customer access tables. Use the speed and park wires above.
Sources: Ford's E-Series Body Builders Layout Books for 2025, 2026 and 2027 (OEM customer access tables). Headlight and CAN wires are not in Ford's customer access tables.
Where are the fuse boxes and ground points on a 2026 Ford E-Series Cutaway?
Ground pointsFord ground pinsPin 3 of C239 (instrument panel) or pin 1 of C338X (bottom of the A-pillar). Never the battery negative post.
RearFrame groundPin 12 of the rear lighting connector is a frame ground at the left rear.
From Ford's 2026 E-Series Body Builders Layout Book. Our team has not yet checked them on a truck.
Where is the OBD-II port on a 2026 Ford E-Series Cutaway?
OBD II
Diagnostic portOBD-II port: lower dash, left of the steering columnPlug-in GPS trackers and OBD harnesses connect here. Check the port before you plan the install.
Which years share wiring with the 2026 Ford E-Series Cutaway?
This page2026Ford's 2026 E-Series Body Builders Layout Book.
Same wiring2025 and 2027Ford prints the same customer access tables in its 2025, 2026 and 2027 books.
Not this page2024 and olderThe 2021 to 2024 pages use an installer sheet and Ford's manuals. 2008 to 2018 have their own pages. Ford built no 2020 E-Series.
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This page covers the 2026 Ford E-Series cutaway and stripped chassis (E-350 and E-450). Ford builds customer access connectors into these trucks for body builders, so a GPS or camera can take power and signals without cutting the factory harness.
Every color here comes from Ford's 2026 Body Builders Layout Book. Our own team has not yet metered these on a 2026 truck, and each row says so.
Written by API Signal, fleet GPS and camera installers for 35+ years across Georgia, South Carolina and North Carolina, installing every major telematics and camera brand. Every wire on this page lists its source.
Test every wire with a meter before you tap it
No wiring information is ever guaranteed. Colors and locations change with trim, options and build date, and the manufacturer can change them in the middle of a model year. We share this as a starting point for installers, and you are responsible for confirming every connection on the truck in front of you.
Common questions about 2026 Ford E-Series Cutaway wiring
What wire is constant power on a 2026 Ford E-Series Cutaway?
Red at the trailer brake controller connector C239, behind the center of the dash, pin 8. Fuse 41 battery feed, for a trailer brake controller. Meter it before you tap it.
Where is the reverse wire on a 2026 Ford E-Series Cutaway?
Green/Brown (positive +) at the rear lighting customer access connector (14406), frame, pin 3. Reverse lamps. Meter it before you tap it.
Where is the brake wire on a 2026 Ford E-Series Cutaway?
Brown/Blue (positive +) at the trailer brake controller connector C239, behind the center of the dash, pin 12. Brake on/off feed. Meter it before you tap it.
Where is the vehicle speed signal on a 2026 Ford E-Series Cutaway?
Violet/Orange at the engine customer access connector 12A581, engine compartment, pin 12. Vehicle speed output from the PCM. Meter it before you tap it.
Which years share wiring with the 2026 Ford E-Series Cutaway?
2025 and 2027. Ford prints the same customer access tables in its 2025, 2026 and 2027 books.
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No one has sent photos for the 2026 Ford E-Series Cutaway yet, so yours could be the first. Every photo, wire color and tip we use goes on this page with your name on it, and it saves the next installer time under the dash.
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