Head light problem

[vtach]

Lights worked fine before. Then noticed when the headlights are on, the driver's side is really dim. When I switch on the highbeams, the passenger side gets dim while the other looks normal. Anyone have an idea what is going on? Can't find any loose wires.
Thank you in advance.

 

[Ferroequinologist]

Ground? could be something with the switch, swap it out and see what happens. If you have a spare. Which you should. If you don't, ask Santa for one. They are handy to have. I've had two go out on me over the years.

 

[vtach]

Its an electronic swith so I will check the ground. If that doesn't work I have a standard swith I can try.

 

[dabtl]

Bjorn will know. Ask him about all things electrical on the deuce.

 

[vtach]

Volt meter says it grounded???

 

[cranetruck]

Yeah, right dabtl...

Vtach, are you measuring your ground return all the way to the battery?

 

[dabtl]

Sorry, Bjorn. I figured you would know the answer by osmosis at least.

But, I cannot think of anyone more able to guide him quicker and more certainly than you.

 

[Ferroequinologist]

Proper installation of an electronic light switch- carry to trash can, drop. Job done.

I personally hate them. Both of the ones I had go out on me were electronic, and before the one went out it would trip if I had a trailer plugged in, it wouldn't even handle the 2 extra lights. Hard to use in the dark when your used to a manual switch.

Just my

 

[bottleworks]

Proper installation of an electronic light switch- carry to trash can, drop. Job done.

I'll buy your broken one if you still have it.

 

[vtach]

No, I only checked the ground wire from the switch to the frame. Now its getting really cold out too. Every thing else lights fine?? How can I check the ground all the way to the battery?

 

[mbwarner]

Start with the bulb ground, and continuity isn't the only concern. A bad ground can test okay with a meter, but not carry the amperage required.

My .02

 

[mbwarner]

Ferroequinologist. I love it...

 

[cranetruck]

Prepare a long jumper wire, clip one end to the neg batt terminal and the other to the headlight return post. If this gives you a working light, then you know that there is a problem with the ground path.
The VOM is not good at measuring low (below 1/10 Ohm) resistances and a good ground connection should be in the milliohm range.
You can, on the other hand, use the DC voltage range on the VOM, with a long jumper to the neg batt terminal again, and measure the voltage at the ground connection of the headlight. It should be zero, when the ground is good (light turned on, of course).

 

[dabtl]

I made a jumper wire at least 10 feet long to test the circuits. I do not recall who suggested it but it was super advice. You just start at the battery and the end of the circuit and keep testing back to the problem. Works great.

And, check the grounds thoroughly. I have gone as far as replacing all the bolts, nuts, washers and cleaning the surface of rust and dirt to the last connection before establishing a solid ground in one instance. The lack of a good ground can make you crazy.