When a sensor wire on your Dodge Ram develops an open-circuit or short-circuit deep inside the engine wiring harness, most folks assume they have to tear the whole thing apart just to find the break.
And in some cases, that's exactly what has to be done —removing the harness to dig in, trace the fault, and either repair it on the bench or replace it entirely.
But there are situations where you don't have to go that far. In this guide, I'll show you a proven repair method I've used successfully many times —one that's simple, reliable, and 100% doable right in your own driveway.
Contents of this tutorial:
APPLIES TO: This tutorial applies to the following vehicles:
- 1989-1993:
- Dodge Ram 150 Pickup 5.2L V8: 1989, 1990, 1991, 1992, 1993.
- Dodge Ram 250 Pickup 5.2L V8: 1989, 1990, 1991, 1992, 1993.
- Dodge Ram 150 Pickup 5.9L V8: 1989, 1990, 1991, 1992, 1993.
- Dodge Ram 250 Pickup 5.9L V8: 1989, 1990, 1991, 1992, 1993.
- Dodge Ram 350 Pickup 5.9L V8: 1989, 1990, 1991, 1992, 1993.
- 1994-2003:
- Dodge Ram 1500 Pickup 5.2L V8: 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001.
- Dodge Ram 2500 Pickup 5.2L V8: 1994, 1995, 1996, 1997, 1998.
- Dodge Ram 1500 Pickup 5.9L V8: 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003.
- Dodge Ram 2500 Pickup 5.9L V8: 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002.
- Dodge Ram 3500 Pickup 5.9L V8: 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003.
What's An Open Or Short Circuit?
First, let me quickly explain the difference between and open-circuit and a short-circuit issue.
An open circuit means the wire is broken somewhere —current can't flow through it at all.
A short circuit means the wire is touching something it shouldn't, like another wire or a metal surface, sending current the wrong way or killing the signal entirely.
Knowing the difference not only speeds up your diagnostic process —it also helps you get the repair done right the first time.
And yeah, this kind of issue is something you're bound to run into sooner or later when working on fuel injection or engine performance problems tied to the engine management system.
Splicing In A New Wire Over The Top Of The Harness
Once you've confirmed there's an open-circuit or short-circuit issue in the wiring between a sensor and the PCM —whether it's the CKP, TPS, CMP, ECT, MAP, or IAT sensor— most DIYers freeze up.
Why? Because these sensor wires run deep inside the engine wiring harness, often wrapped in tape, routed behind engine components, and completely invisible to the eye.
The idea of physically tracing the wire from end to end sounds like a nightmare —and in truth, it is.
But here's the good news: you don't have to do that.
In my "too long" automotive repair career, I've dealt with this exact issue on many vehicles, and I can tell you from experience that there's a faster, easier, and completely reliable fix: splice in a new wire over the top of the harness.
Now, if the damaged section is easy to reach —and we’re only talking about one or two wires— then by all means, repair that section directly.
Whether that means wrapping up the wire with electrical tape or soldering a clean splice, it’s always best to fix the problem in place if you can access it without tearing apart half the engine bay.
But when access is limited or the wire is buried too deep to get to without a lot of disassembly, here’s the workaround I recommend —and have used countless times myself:
- Cut the affected wire several inches away from the sensor connector —far enough to reach clean, undamaged copper.
- Do the same at the PCM connector side, leaving yourself room to work.
- Run a new wire of the same gauge along the outside of the harness —zip tie it in place to keep it secure and prevent chafing.
- Solder both ends of the new wire to the original harness wires.
- IMPORTANT: Do not use butt connectors. They may seem convenient, but they loosen over time from vibration and heat, leading to intermittent faults or total signal loss.
- Protect each solder joint with heat shrink tubing or high-quality electrical tape to guard against moisture and corrosion.
This method is safe, effective for small gauge engine management sensor signal wires (see: Important Safety Note About This Repair).
I've used this approach countless times and it has helped me avoid hours of unnecessary harness teardown, and if done right, the repair will hold up over the long haul.
So, don't let the idea of a "buried wire break" scare you. You don't need to rip the truck apart or be an electrical specialist.
The following article may also be of help:
Important Safety Note About This Repair
This repair method is meant only for low-voltage sensor/PCM circuits. It applies safely and effectively to:
- Sensor signal wires.
- Sensor Ground wires (that go to the PCM).
- 5 Volt reference wires.
- Small-gauge chassis Ground wires.
These wires carry very low voltage and minimal current —nothing that can overload the wire, start a fire, or damage the harness when repaired properly.
Do Not Use This Method On 12 Volt Power Feed Wires. These circuits power fuel injectors, ignition coils, and other high-current components.
A damaged 12V feed wire requires a full inspection and, often, a completely different repair approach using properly rated wire, protection, and routing.
If your engine wiring harness has suffered a fire or severe melting, the correct repair is to replace the entire harness. See:
Bottom line: The splice-over technique shown in this tutorial is safe, long-lasting, and proven —but only when used on the low-voltage circuits listed above. Know the circuit you're working on before applying this fix.
More 5.2L, 5.9L V8 Dodge Ram Pickup Tutorials
I've written several more tutorials for the V8 Dodge Ram pickups that may be of interest to you that you can find in this index:
Here's a sample of the tutorials you'll find in the index:
- Troubleshooting A Blown Head Gasket (1989-2003 5.2L, 5.9L V8 Dodge Ram Pickup).
- How To Test The TPS (1992-1996 5.2L, 5.9L V8 Dodge Ram Pickup).
- How To Test The MAP Sensor (1992-1996 5.2L, 5.9L V8 Dodge Ram Pickup).
- How To Test The Intake Air Temp (IAT) Sensor (1992-1997 5.2L, 5.9L V8 Dodge Ram Pickup).
If this info saved the day, buy me a beer!
