I'm having a problem with my 03 RK and I took a voltmeter to the plugs in the tail lamp assembly. I get voltage on all connections.
I placed the neg lead on the top neg black wire in the plug on the far right side and I get 11.6, v and 30ish v I think on the other connections as I moved the red lead to other pins in the housing so voltage is coming through. I have tried new bulbs in the past but it didn't help. It could be the harness but I'm not sure the part number for the bulb harness
How can I test? I need to understand the parameters on all the possible test steps. I get resistance also when I test the harness pins with the bulb in.
there used to be a running light and no brake but now there is nothing. What should the voltage be before engaging the brake and after? And where do you test?

 

Pull the bulb and inspect the contacts on the base of the bulb as well as inside the socket.
This bulb design has a very small “contact patch” between bulb contacts and socket contacts, which tends to overheat and corrode those tiny spots.
You’ll still be able to measure voltage at the socket because the probe tips are contacting a clean portion of the contacts.
The bulb will also pass a continuity check, except if you measured through those burnt/corroded contact points.
I just fixed this for a buddy on his ‘07 RK by replacing the socket w/ a good, used unit.
This can also be eliminated (for good) by upgrading to an LED assembly, which plugs into the main wiring harness, bypassing this particular failure mode.

 

Well, I am very happy to replace it with an LED. I just bought a an entire tail light, but it failed only the blinkers work not the break or the running for the license plate light. I need more specifics on how to test it with the boat meter but I have them handy it’s too hard for me to go to the bike right now, so what test can I do with voltmeter and tell him pigtail and bulb in my hands?

 

I just did a continuity test with the bulb plugged in at the plug from the black to the red and from the black to the blue and I get 4.4 on the red and 3.0 on the blue so it seems that there is resistance and continuity is functioning through the both low and the high element of the bulb

so now I’m not sure what the check next to them because I got a voltage on all of the things they tested in the harness or the circuitboard with the plugs but I’m willing to review that because I’m not sure I did it right but this doesn’t seem to make a lot of sense and it’s both hand and foot brake and of course, again the running light doesn’t function either and the fuses have been checked but please let me know again which fuses would be implicated because I would check them again as well

 

Every LED taillight that I have seen/installed has a plug that goes into the main wiring harness.
The factory tail light has a short pigtail; one end being the lamp socket, the other end connecting to the main harness.
If replacing the entire assembly w/ LED doesn’t solve the problem, it is likely an issue in the portion of the main harness that is inside the rear fender.
If the bike is, or has ever been lowered, or the rear tire size has been altered, then it is very possible that wires have been rubbed through their insulation. Probably really hard to see/confirm with the rear tire in place unless you can lift it by the frame and let the swingarm sag by releasing the lower shock bolts.

 

The bike in stock hasn’t had any modifications that would impede on the harness underneath so therefore, that’s why I wanted to do tests on the sockets in the harness itself because if they’re producing voltages, then it would indicate that there’s nothing wrong with the wiring so the voltage as I saw were generally 11.6 and 30 maybe it was 30 mV I’m not rusher if it was 30 V or 30 mV and other numbers I think possibly but I don’t recall exactly but there is always voltage coming. I would like to go and retest if I have actual information on how to perform the test correctly and what the numbers should look like. I will do that when I receive some thing I can understand and in an hour when the heat is down a bit more

 

Also, what is this plug for because I don’t know if it was ever connected to anything and I forgot or if it’s an optional accessory. this is on the fuse block side

 

OK now I’m really confused so it’s not the bulb and it’s not a harness the pigtail I mean but I noticed that the four pins that the harness plugs into if I short two of them then one light comes on and if I short another two pins the other light comes on, so I don’t know what to do from this point, but no light comes when it’s turned on and it should have the tail lamp on and then the brake lamp when you hit the brakes but it doesn’t. I don’t know why these things light up only when I short them I hear the relay click on and the voltage changes when I hit the relay when I hit the break I mean, but I don’t know what to do and also the running late at the very bottom of the fender doesn’t work I don’t know why, but that’s just another aside.