Rear Blinkers not working??

[barillms]

I bought an 03 Ram, it has 120k miles... good running truck. Anyway,

Front Blinkers work fine.
Rear blinkers ...NEITHER side works. Hazards in the rear dont work.
Changed the bulbs, Nothing.

The taillights and brake lights work perfect. No trouble.
just the rear blinkers. I have no idea what it could be.

I even took apart the steering column, to access the MFS (blinker switch) and pulled it off. Cleaned it... still nothing.

Looks like the prev owner hit a pole and ripped the right rear taillight assembly off. Why would this affect the left side blinker?

I checked the plug connections, i also traced the taillight wire bundles looking for a ground wire. No ground wires?? It has to be a loose ground, but i cannot find a ground wire.

I checked the fuses, theyre fine.

 

[Ramunit]

The circuit boards within the taillights themselves that the bulbs plug into are known to short out fairly regularly. Replacements cost around $24

 

[MegaMouseGW]

This sounds like a problem in the computer and not wiring. What tells me this is that your running lights and brake lights both work. The blinkers use the same part of the bulb that the brake lights use. You said that you replaced the bulbs and they work fine so it is not a circuit problem in the taillights themselves. Not sure just how much the computer in an 03 controls but unless their is a short between the switch in the steering column and where the connector for it goes into the main harness I would guess computer.
Using a multimeter disconnect the steering wheel connector, locate which wires are for the blinkers and start seeing if they are not shorted out.
As far as a ground wire there are several on Dodge trucks. You will have one from the bed to the frame, not sure the exact spot though, and the main harness will have several coming out f it at several places. Seeing as your brake lights, and running lights work fine I do not think it is a grounding issue. Good luck.

 

[barillms]

Would one bad inner circuit board affect the other light?
I would think if one of the circuit board things was bad it would affect all 3 bulbs within that light cluster?

 

[MegaMouseGW]

Just one bad circuit board will not effect all the lights. I was thinking upon this while riding around town today and said to myself "maybe he has an issue with his blinker relay". Not sure if the rear and front blinkers are on separate relays (most likely not), but I do know BMW has a 2 sided relay that one side controls the rear blinkers and the other side controls the front blinkers. If tis is the case with your Ram then changing out the blinker relay might be the fix. Try that out if you haven't already.
Looking at E-Bay I need to ask this: Are the blinkers in with the brake lights or are they the middle lights?? If they are the middle one then I may be a bit wrong. It could be the rear circuit board, but one going out should not affect the other.

 

[Ramunit]

One circuit board could affect the other since pcm needs to read a complete circuit around the truck or it is possible both circuit boards are out in the same place but by no means stop exploring other ideas.

 

[quietpeen]

i would definitely look at the circuit boards. Take the lights off and remove the boards. If the plastic is melted and discolored around the bulbs it a good chance that is your issue.

 

[HolyRamBatman]

While you have the light out. Check the connector with a multimeter for power when blinkers are on.

 

[MegaMouseGW]

While you have the light out. Check the connector with a multimeter for power when blinkers are on.

This was my next suggestion. While you have the lights out turn on the hazards, and while using a multimeter check for 12volts (give or take a few volts) going through the connectors. Just stick the negative probe on bare metal and start poking the pins with the red probe. No voltage means something other than the circuit boards.