Which wires give constant, ignition and ground on a 2020 Ram 2500 / 3500?
On a 2020 Ram 2500 / 3500, take constant power from the Red wire behind the push-to-start button, ignition from the Pink/White wire at the body control module, left side of the dash, gray/black 48-pin plug, pin 27, and ground to the Black wire behind the push-to-start button. 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:Start button harness and body module, left of the dashSystem voltage:12VIgnition type:Push-button (this page)
Power: two places
Constant and ground are at the push-to-start button harness. Ignition is at the body control module on the left side of the dash.
Constant and ground
Start button harness
Behind the push-to-start button.
Constant
Red
Behind the push-to-start buttonAlways hot, 12V.
Ground
Black
Behind the push-to-start buttonGround wire.
The start button wire in the same harness is Purple/Brown. Never tap that one.
Ignition
Body control module
Left side of the dash.
Ignition
Pink/White
Body control module, left side of the dash, gray/black 48-pin plug, pin 27Hot with the truck on. Fortin and Kleinn agree.
Meter it: dead with the truck off, 12V with it on.
From Fortin's install guide for the 2019 Ram 2500, 3500 and 4500 with push-to-start (Fortin lists it for 2019 to 2024 gas trucks) and Kleinn's RSRAM72 install sheet. The guide does not print pin numbers.
Where are the turn signal, reverse and light wires on a 2020 Ram 2500 / 3500 for advanced 360 multicam and video telematics installs?
Circuit
Wire color
Location and what it does
Left turnNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Right turnNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Park lightDataNot yet checked
White/Brown
Headlight switch, gray 10-pin plugFortin marks this as a multiplexed (MUX) switch signal, not a 12V lamp feed. Do not use it as a 12V sense input.
HeadlightNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
ReverseNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Dome lightNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Each chip shows the main insulation color with its stripe. Source: Fortin's install guide for the 2019 Ram 2500, 3500 and 4500 with push-to-start (Fortin lists it for 2019 to 2024 gas trucks) and Kleinn's RSRAM72 install sheet.
Where are the brake, door, speed and CAN wires on a 2020 Ram 2500 / 3500 for advanced 360 multicam and video telematics installs?
Circuit
Wire color
Location and what it does
Push-button startDataNot yet checked
Purple/Brown
Behind the push-to-start buttonStart button signal (positive), per Fortin. Never tap it.
DataDataNot yet checked
White/Green
Behind the push-to-start buttonData wire. Never tap it.
BrakeNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
DoorsNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Parking brakeNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Vehicle speedNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
CAN dataNot foundNot yet checked
Not found
CAN junction, left side of the dash, white 2-pin plugFortin shows the CAN junction here but prints no colors. Never cut or splice the CAN wires.
Source: Fortin's install guide for the 2019 Ram 2500, 3500 and 4500 with push-to-start (Fortin lists it for 2019 to 2024 gas trucks) and Kleinn's RSRAM72 install sheet. Turn, reverse, headlight, dome, brake, door, parking brake, speed and CAN wire colors were not found.
Where are the fuse boxes and ground points on a 2020 Ram 2500 / 3500?
InteriorFuse panelNo fuse position for these years was found in a source. Read the lid label and meter the slot.
Body moduleLeft side of the dashGray/black 48-pin plug, ignition at pin 27, per Kleinn.
Ground pointsBlack wire at the start button harnessOr clean body metal. Never the battery negative post.
Locations from Fortin's install guide.
Where is the OBD-II port on a 2020 Ram 2500 / 3500?
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 2500 / 3500?
This page2020Ram 2500 / 3500, gas, push-button start.
Not this page2018 and olderOlder generation with different wiring.
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This page covers the 2020 Ram 2500 and 3500, including chassis cab trucks, with a gas engine and push-button start.
The wire colors come from Fortin's install guide, read wire by wire, and the ignition wire is confirmed by Kleinn's install sheet. Our own team has not yet metered these on a 2020 truck.
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 2500 / 3500 wiring
What wire is constant power on a 2020 Ram 2500 / 3500?
Red behind the push-to-start button. Always hot, 12V. Meter it before you tap it.
What wire is ignition on a 2020 Ram 2500 / 3500?
Pink/White at the body control module, left side of the dash, gray/black 48-pin plug, pin 27. Hot with the truck on. Meter it before you tap it.
Which years share wiring with the 2020 Ram 2500 / 3500?
2019, 2021, 2022, 2023, 2024. Fortin lists one guide for 2019 to 2024.
Help build this page
Had the panels off on one of these? Show the next installer what you found.
No one has sent photos for the 2020 Ram 2500 / 3500 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.
1. Snap it
The plugs, tap points, fuse boxes and ground points. Phone photos are fine.
2. Send it
Tap "Add yours" at the top of this page. Your tip and your photos go in the same box.
3. See your name on it
We check every tip, then post it here "Compliments of" you, by name.
Compliments of
The installers who helped build this page.
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Founding contributor spot: openThe first installer to confirm a wire or send photos for the 2020 Ram 2500 / 3500 gets their name here, and it stays here.
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Every tip we use gets a creditThe wire you checked is marked "Checked on a truck, compliments of" you.
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