I am about to give up on this 83 .... Dim low beam

[MasterGuns]

I have been chasing this problem for way too long. So before I have this bike sent to a salvage yard, I am going to reach out to the experts.

 

Problem - low beam is way to dim.

 

1. Bulb has tested good.

 

2. Dimmer switch replaced and is good as well as clean.

 

3. Not real sure how to check the reserve lighting unit but I have three of them and same symptom with all three. This pretty much eliminates a bad RLU.

 

4. I also removed the CMU to check for a faulty solder point and could not identify any but re-soldered the plug solder points anyway. Reinstalled - dim low beam still. Since I had another complete dash unit, I checked the replacement dash and found no issues and installed that one. Still a dim low beam.

 

High beam is as bright as it should be, just a dim low beam. Battery is 12.6.

 

How should I proceed from here?

 

I'd hate to part this thing out; it runs just too good to do that.

 

Thanks in advance for your help.

 

herb

[Squeeze]

I'd take a Look into the High/Low Switch on the left Handle Bar. Those Contacts are often corroded and cause a lot of Resistance.

[Flyinfool]

Start at the very beginning, it is a very good place to start.......

 

Get your volt meter ready. connect the black lead to battery negative.

Prepare the red lead with a very sharp point or attach a pin or needle.

All readings should be very close to your 12.6V that you have at the battery.

Use the pin or needle to poke thru the wire insulation to check voltages.

At the dimmer switch there are 3 wires, the green is the low beam. Check power.

Follow that wire to a 3 pin connector, the green on both sides of that connector should be 12 V.

follow to the CPU, check voltage at the CPU green wire.

Coming out of the CPU it is now the green/red wire, 12v. at CPU.

Check the green/red wire at the headlight bulb for 12v

Check the green/red wire at both sides of the RLU connector for 12v.

 

This should keep you occupied for a while and very likely narrow down the issue.

[MasterGuns]

Jeff/Squeeze, Figured things out. Doing as you suggested Jeff and when I started to check the out voltage on the green/red wire I had to jiggle the wires around a bit to expose a part of the g/r wire to gain access in order to insert the safety pin I was using. Upon the jiggling process the g/r wire just fell out of the connector. It was badly corroded so it didn't take much movement to break free. I finally managed to get the little connector out of the plastic plug but in doing so I gurred it up pretty good. Fortunately I have a spare harness that I removed a like metal connector soldered it to the r/w wire and inserted it back into the plastic plug. No more dim low beam.

 

If I had not been following your instructions I would never figured out the problem.

 

Thank you you so much.

 

Herb

[Flyinfool]

Cool, glad you got it. I figured it was a bad connection somewhere and this is the only way I know to track it down.

Edited January 7, 2015 by Flyinfool

[flyday58]

Darny darn, I was hoping to pick up a spare 83 cheap!

Always glad when someone gets one of these sorted.