Which wires give constant, ignition and ground on a 2020 Ram 3500, 4500 and 5500 Chassis Cab?
On a 2020 Ram 3500, 4500 and 5500 Chassis Cab, take constant power from the fuse tap in the cab fuse panel (wire color not published), ignition from the Pink/Yellow wire at the VSIM black 16-cavity jumper, pin 13, and ground to the Black wire at the VSIM brown 16-cavity jumper, pin 16. Meter every wire first.
Meter every wire before you tap it. Colors change with trim and build date.
OBD-II port:Location not confirmedBest power spot:VSIM jumpers under the columnSystem voltage:12VUpfitter module:VSIM, standard
Where do I get constant, ignition and ground on a 2020 Ram 3500, 4500 and 5500 Chassis Cab?
Every 2019 and newer Ram chassis cab has the Vehicle System Interface Module (VSIM), Ram's upfitter module, with blunt-cut jumper wires for ignition, lamps, doors and gear position.
Option 1 Ignition sense
VSIM jumper harnesses
The VSIM sits under the steering column behind the knee blocker. The black, brown and green jumpers plug straight into it.
Ignition
Pink/Yellow
VSIM black 16-cavity jumper, pin 13Power feed "Run/Start" status: +12V with the key in run or start. Rated 0.5 amp, so use it as an ignition sense, not to power a device.
Fuse tap in the cab fuse panelThe VSIM has no battery feed. Use an add-a-fuse on a slot that stays live with the key off.
Pin 5 of the black jumper (Pink) is the "Off" status feed, live only with the key off.
Option 2 Signals
VSIM gray 24-cavity connector
In-line, above the accelerator pedal bracket.
Park light
White/Green
VSIM green 16-cavity jumper, pin 15Park lamp on signal.
Reverse
Dark Green/Dark Blue
VSIM gray 24-cavity in-line connector, pin 12Transmission in reverse.
Door ajar
Violet/Orange
VSIM gray 24-cavity in-line connector, pin 17Any door ajar.
These are VSIM outputs. Use them as sense inputs only.
All colors from Ram's VSIM body builder instruction (FCA, March 2019), which Ram lists for the 2019 and 2020 chassis cabs. The VSIM only works with the vehicle awake (key on).
Where are the turn signal, reverse and light wires on a 2020 Ram 3500, 4500 and 5500 Chassis Cab for advanced 360 multicam and video telematics installs?
Circuit
Wire color
Location and what it does
Left turnPositive +Not yet checked
White/Blue
VSIM black 16-cavity jumper, pin 3+12V pulses with the left turn signal. 0.5 amp.
Right turnPositive +Not yet checked
White/Dark Green
VSIM gray 24-cavity in-line connector, pin 4+12V pulses with the right turn signal.
Park lightPositive +Not yet checked
White/Green
VSIM green 16-cavity jumper, pin 15Park lamp on.
HeadlightPositive +Not yet checked
White/Brown
VSIM green 16-cavity jumper, pin 7Low beam active. High beam is White/Violet, black jumper pin 4.
ReversePositive +Not yet checked
Dark Green/Dark Blue
VSIM gray 24-cavity in-line connector, pin 12Transmission in reverse position.
Each chip shows the main insulation color with its stripe. Source: Ram's VSIM body builder instruction (FCA, March 2019), which Ram lists for the 2019 and 2020 chassis cabs.
Where are the brake, door, speed and CAN wires on a 2020 Ram 3500, 4500 and 5500 Chassis Cab for advanced 360 multicam and video telematics installs?
Circuit
Wire color
Location and what it does
Door ajarPositive +Not yet checked
Violet/Orange
VSIM gray 24-cavity in-line connector, pin 17Any door ajar.
Parking brakeNegative -Not yet checked
Dark Green/White
VSIM brown 16-cavity jumper, pin 11Park brake applied, low side (ground) output.
In parkPositive +Not yet checked
Yellow/Dark Blue
VSIM gray 24-cavity in-line connector, pin 7Transmission in park.
HazardPositive +Not yet checked
White/Blue
VSIM gray 24-cavity in-line connector, pin 2Hazard indicator on.
Vehicle speedNot foundNot yet checked
Not found
Not foundSpeed is sent on the VSIM J1939 bus, not on a single wire.
CAN busDataNot yet checked
Not found
VSIM J1939 outputThe VSIM sends J1939 messages for upfitter equipment. Never cut the truck's own data wires.
Sources: Ram's VSIM body builder instruction (FCA, March 2019), which Ram lists for the 2019 and 2020 chassis cabs; Ram's auxiliary switch body builder instruction (April 2019). No cab constant wire color was found.
Where are the fuse boxes and ground points on a 2020 Ram 3500, 4500 and 5500 Chassis Cab?
CabFuse tap for constantThe VSIM has no battery feed. Read the fuse panel label and pick a slot that is live with the key off.
UpfitterAux power distribution centerTrucks with aux switches have relay outputs at two 4-way connectors on the inboard side of the aux PDC. Ram supplies the wires in a kit.
Ground pointsVSIM brown jumper pin 16Black ground return, or clean bare cab metal. Never the battery negative post.
From Ram's VSIM body builder instruction (FCA, March 2019), which Ram lists for the 2019 and 2020 chassis cabs and Ram's 2019 auxiliary switch instruction.
Where is the OBD-II port on a 2020 Ram 3500, 4500 and 5500 Chassis Cab?
OBD II
Diagnostic portOBD-II port: location not confirmedLook under the driver side dash first, and send us a photo if you find it.
Which years share wiring with the 2020 Ram 3500, 4500 and 5500 Chassis Cab?
This page2020Ram 3500, 4500 and 5500 chassis cab.
Same wiring2019Ram lists the same VSIM instruction for 2019 and 2020.
Not this page2018 and olderNo VSIM before 2019. Ram 2500 and 3500 pickups have their own pages.
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This page covers the 2020 Ram 3500, 4500 and 5500 chassis cab. From 2019 Ram builds its Vehicle System Interface Module (VSIM) into every chassis cab, with labeled blunt-cut wires for upfitters.
Every color here comes from Ram's own VSIM body builder instruction. Our own team has not yet metered these on a 2020 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 2020 Ram 3500, 4500 and 5500 Chassis Cab wiring
What wire is ignition on a 2020 Ram 3500, 4500 and 5500 Chassis Cab?
Pink/Yellow at the VSIM black 16-cavity jumper, pin 13. Power feed "Run/Start" status: +12V with the key in run or start. Meter it before you tap it.
Where is the reverse wire on a 2020 Ram 3500, 4500 and 5500 Chassis Cab?
Dark Green/Dark Blue (positive +) at the VSIM gray 24-cavity in-line connector, pin 12. Transmission in reverse position. Meter it before you tap it.
Where is the brake wire on a 2020 Ram 3500, 4500 and 5500 Chassis Cab?
Dark Green/Orange (positive +) at the VSIM black 16-cavity jumper, pin 11. Service brake pedal pressed. Meter it before you tap it.
Where is the parking brake wire on a 2020 Ram 3500, 4500 and 5500 Chassis Cab?
Dark Green/White (negative -) at the VSIM brown 16-cavity jumper, pin 11. Park brake applied, low side (ground) output. Meter it before you tap it.
Where is the CAN bus on a 2020 Ram 3500, 4500 and 5500 Chassis Cab?
The wire color is not published. It is at the VSIM J1939 output. The VSIM sends J1939 messages for upfitter equipment.
Which years share wiring with the 2020 Ram 3500, 4500 and 5500 Chassis Cab?
2019. Ram lists the same VSIM instruction for 2019 and 2020.
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Tap "Add yours" at the top of this page. Your tip and your photos go in the same box.
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Compliments of
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