- Joined
- Jan 18, 2026
- Messages
- 3
- Points
- 1
- City
- Topeka
- State - Country
- KS - USA
- Vehicle Year
- 2002
- Vehicle
- Ford Ranger
- Drive
- 4WD
- Engine
- 4.0 V6
- Transmission
- Automatic
This is not like every other bad trailer ground wire causing issues post, so please read this if you have any knowledge about this topic. I've posted about this before but to no avail. I've messed with it for a few months here and there but I'm coming back here to look for any extra advice. I have a 2002 Ranger XLT 4.0L. Without my headlights or running lights on, everything works just fine. When I do have any of those on, here is what happens:
Left turn signal is turned on:
Solid front turn signal light, solid slightly brighter rear left light, solid significantly dimmer rear right light.
Right turn signal is turned on:
Normal operation of right front and rear lights, solid slightly brighter rear left light.
Also note that my brake lights do not seem to turn on very bright if my headlights or running lights are already on.
I've become very well versed and understand this is a common issue after reading so many threads on here and other places. I have sanded down ground 103 on the driver's side of the engine compartment and confirmed continuity to battery ground. Cut and capped all trailer wires and confirmed ground continuity from the trailer ground wire back to battery ground. I replaced the bulb and socket for the left front and rear turn signals. I found some resistance in a ground wire from a headlight to battery ground so I replaced that wire and no changes. I have confirmed continuity to ground to battery ground from every headlight, turn signal, running light, and tail light. Looked at a diagram saying that the tail lights ground to ground 203 on the passenger side rocker panel and found that it was broken so I replaced that with a battery ground cable and it did nothing.
Pretty much running out of things to do without just throwing parts and wires at this truck. Does anyone know any special tricks about this? Any other ground spots that this circuit could be failing to ground to? If so where are they? If you need any extra information to figure this out let me know and I will get it for you.
Left turn signal is turned on:
Solid front turn signal light, solid slightly brighter rear left light, solid significantly dimmer rear right light.
Right turn signal is turned on:
Normal operation of right front and rear lights, solid slightly brighter rear left light.
Also note that my brake lights do not seem to turn on very bright if my headlights or running lights are already on.
I've become very well versed and understand this is a common issue after reading so many threads on here and other places. I have sanded down ground 103 on the driver's side of the engine compartment and confirmed continuity to battery ground. Cut and capped all trailer wires and confirmed ground continuity from the trailer ground wire back to battery ground. I replaced the bulb and socket for the left front and rear turn signals. I found some resistance in a ground wire from a headlight to battery ground so I replaced that wire and no changes. I have confirmed continuity to ground to battery ground from every headlight, turn signal, running light, and tail light. Looked at a diagram saying that the tail lights ground to ground 203 on the passenger side rocker panel and found that it was broken so I replaced that with a battery ground cable and it did nothing.
Pretty much running out of things to do without just throwing parts and wires at this truck. Does anyone know any special tricks about this? Any other ground spots that this circuit could be failing to ground to? If so where are they? If you need any extra information to figure this out let me know and I will get it for you.
