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How to test for power at LED turn signal? using a multimeter

How to test for power at LED turn signal? using a multimeter

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  #1  
Old 05-16-18, 12:27 PM
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How to test for power at LED turn signal? using a multimeter

So my right front run signal went out .
The turn signal is an LED embedded within the mirror.
To replace it they don't sell the LED separately you have to buy a new pair of mirrors.
Before I head down that path I want to ensure power is getting to the LED first.
How would I do that using a multimeter?
 
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  #2  
Old 05-16-18, 02:32 PM
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Hi, I would set the multi meter to DCVolts and put one lead to ground and the red lead to the red solder joint on the board then active the switch that should turn the light ON. Is there a connector on one end of the wires? You should che k there also.

Geo
 
  #3  
Old 05-16-18, 02:40 PM
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I did that and the reading was 0.0
 
  #4  
Old 05-16-18, 03:01 PM
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How about checking for a blown fuse? That red wire looks a bit squished, has any work been done on the bike?
Geo
 
  #5  
Old 05-16-18, 05:17 PM
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Looked at the fusebox. All the lights are on one fuse. Pulled it and it's good, that and the other lights all work.
Recently installed LEDs, that's the only mod. I did notice once the LEDs went out for a second then came back on, maybe that's what blew the turn signal.
 
  #6  
Old 05-16-18, 05:39 PM
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Did you do the Mod? Did you check that Red wire that looks squished? Can you determine if that White wire is ground? I would think it might be and is there a connector on one end of the wires I would remove that light and put 12 volts DC across the terminals and see if it lights, it could be a bad switch.
Do you belong to any HD forums,it might be worth putting the problem out there and see what comes back also.
Keep us posted of the outcome
Geo
 
  #7  
Old 05-16-18, 05:58 PM
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I didn't do the mod and it was working at first.
The red wire looks squished but I don't think it is, I'll check when it's light out tomorrow.
Those wires are soldered onto that board so removing may not be an option.
Could I still put 12v DC across the terminals and if so, how?
I belong to HD forums but this is an aftermarket kit.
 
  #8  
Old 05-16-18, 06:52 PM
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I would test to ground with the multi meter, one lead to frame on bike and the other to the white lead on the board and see if you have continuity, I really would you to isolate that board from the bike before putting the 12 volts to just to be sure nothing could back feed into that circuit,itís not that hard to unsolder those terminals, your call ,you could also cut the wires and resplice with some small butt splices.
Geo
 
  #9  
Old 05-17-18, 05:01 AM
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None of the red wire is exposed, only the sheathing is squished.
If I turn on the turn signal and the rear on is flashing, and I touch the black multimeter wire to the frame and the red multimeter wire to the red soldered joint:
with the multimeter set to DCV-200m it flickers from -00.4 to -00.6 to -00.8
with the multimeter set to DCV-2,000m it flickers from -000 to -001
with the multimeter set to DCV-20 it stays at 000
 
  #10  
Old 05-17-18, 05:23 AM
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I am not sure what that means, what type of meter are you using? Post a pic of the front of it, so the rear directional is working so that would indicate that the switch is OK, is that light on the mirror also a marker light or just directional?
Who is the mfg.? As far as that being an after market item I am sure there are HD riders that use AM parts, ask the question on the forum, what do you have to loose?
A test light like this may be a better choice if your not comfortable with the meter.

https://shop.advanceautoparts.com/p/...486/25989105-P
Geo
 
  #11  
Old 05-17-18, 05:47 AM
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The light on the mirror is only a turn signal, if I don't push the turn right button, nothing would light up.

I don't know who the mfg is but I'll post on the HD forum and see if anyone recognizes it.

I tried the test light prior to the multimeter, I clip it to the frame and touch the solders, nada.
 
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  #12  
Old 05-17-18, 07:33 AM
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I need a new test light.
I clamped mine to the frame, touched it to the soldered joints on the left (working) turn signal and it didn't light up as it should have.
 
  #13  
Old 05-17-18, 09:36 AM
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Ha, that meter looks like a Freebee from HF, put the black lead in the common port and leave the red where it is, set the knob to 20 VDC, to prove its working put black lead across the negative terminal on the battery and red on the positive post on the battery ,you should read battery voltage. Is there any type of connector on the opposite end of those red and white wires?
Geo
 
  #14  
Old 05-18-18, 11:00 AM
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The HF freebee holds at 0.00 but boy those wires are hot.
I tried a different test light also on the working turn signals, nothing.
 
  #15  
Old 05-18-18, 12:01 PM
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Which wires are HOT? Did you test the meter across the battery terminals to be sure the meter is working also the test light? Make sure that switch in the center of the meter is turned on,If you tested a working turn signal and you didnít see any voltage then you are doing something wrong, you didnít say if there is a connector on the opposite end of those red and white wires ?
Geo
 
  #16  
Old 05-18-18, 01:58 PM
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Flashing lights on a car or motorcycle are typically too fast for a digital meter to read. An anolog one will do a better job. You should be reading something around 12 VDC at the light when it is working. You could also test the LED light by connecting 12 volts directly to is by passing all the controls. If it lights then you know your issue is before the lights.
 
  #17  
Old 05-21-18, 03:38 PM
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No power to the turn signal.
Turns out the wire came loose out of the butt connector near the fork
 
  #18  
Old 05-21-18, 04:50 PM
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Thanks for letting us know, often times itís something simple.
Geo
 
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