I hope everyone had a great Christmas and a great New Year.

My issue is that my hi beams only work "sometimes". I normally ride with my brights on all the time. I've been told before, that when my low beams are on, they can't really be seen. (Softail Custom with a small head light)

I've tried replacing the bulb several times. I took it to the dealer, and they said they couldn't recreate the problem, so they put some dielectric grease on the contacts and called it good.

Yesterday, my buddy says "your headlight doesn't come on ?" Sure enough, the high beam shut off. But when I put the low beam on, it worked fine.

I just checked the high beams and they are still not working.

Before I go and replace the bulb again, Where should I check for a short, and what should I have my volt meter set to ?

Thanks.

 

throw 12v to both sides of the bulb and see if the bulb is defective , but after (you say) several I would be looking for a short in the wiring or the switch itself

Mike

 

If you are checking the wiring w/the battery disconnected you will want your meter set to ohms. Otherwise, w/the battery connected and switch on high beams, ground your black lead and check each side of the switch w/the red lead. At this point your meter should be set on DCV. If you get 12V on each side of the switch...the switch is good. I would check the connection to the bulb @ this point if the switch tests good. Hope this helps

 

Thanks for the help guys. I'll keep ya posted.

 

Maybe the Lo/Hi switch itself. Pop it open and see if it's wet or dirty in there, can't hurt...

Start simple...


Mike.

 

If there were a short, a fuse would blow, or breaker would trip.

Both high and low beam get power from the same fuse/breaker, so if there were a short, and fuse/breaker popped, you would have no headlight at all.

It may be a bad connection somewhere between the switch and the headlight connector, or even a bad connector.

Grab your voltmeter.

Turn the high beam on.

Ground the voltmeter negative probe to the negative battery post.

With the headlamp removed from the connector, read the voltage by touching the (+) probe to the terminal at the white wire in the connector. If you see low or no voltage, you need to start tracing back the circuit.

If you read normal voltage while the bulb is out, continue:

Install the bulb into the connector and touch the (+) probe to the white wire terminal in the headlight connector.

What year is the bike?

 

2010 Softail custom.


UPDATE: "Murphy" (me) left his voltmeter on and the battery was dead. So what I did was dropped the headlight and tested with a new bulb. The new bulb worked just fine (high and low beam) so I figured that it was for once, a burnt bulb. I continue to tear down the assembly to look at the old bulb and install the new bulb when I find that the old bulb looks just fine. I put in the old bulb, and it now works just fine. After testing it to make sure it worked, I added some bulb grease to the prongs. I fired up the bike and let it run for about 10 min. or so. The bulb never went out.
I tried the switch, and both high and low beams work.

FML. I HATE electrical gremilins.

 

I think I have done that a couple dozen times...

Since the low beam is not affected, we know the issue is somewhere between the high/low switch and the headlamp connector.

The wire you are following is white.

It may be nothing more than a bad connection. The first place I would suspect is at the headlamp connector, they get pretty hot.

Make sure the spade connector is a snug fit.

 

Thanks !

Today I took the bike out and left the brights on. When I got home I noticed the light was out. I went inside and when I came back out, the lights were working. I tested the white to black lead and got 12 volts.
I then checked the 2 yellow wires (low beam ?) to the black wire and also got 12 volts.

I took the left switch housing apart (My wires run inside the bars so I can't fully remove everything) The inside of the housing looked clean..
(I did notice that from the switches I have 1 White, 1 Yellow, and 1 blue (blue from fuse box) wires)

The white wire at the light bucket looks clean and tightly crimped to the spade, but the spade itself has some play within the plastic housing.

 

I apologize if this has already been covered could it be a relay? I saw another headlight post that mentioned a headlight relay and make sure none of the connections are corroded or loose.