ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 06-04-2014, 07:15 PM   #1
DustyOne OP
Riding@6500' & up
 
DustyOne's Avatar
 
Joined: Oct 2006
Location: Shaken not stirred
Oddometer: 359
R75/6 - problem with left-side switch, and/or headlight

This is a new to me 1975 R75/6 motorbike
very nice condition, runs and pulls quite well
EXCEPT THIS:

the headlight low & high beam DO NOT work as they should
lo beam---does not work when left side switch is in the low position(so it NEVER works)
high beam---- does not work when left side switch is in the high position
HOWEVER
IF I flip the HI Flash switch, the headlight does indeed come on.....but immediately goes OFF when I release it.

upon taking the headlight ring off, inside it looks as new & clean as a sushi cutting table

when tested with a battery on the bench, the headlight when removed from the motorbike, the H4 light is good for both low and high

everything APPEARS to be connected EXCEPT 1 wire, it is a black with a female plug on the end that looks like one of those plugs that connect to a Japanese Bikes Horn....but with the left switch, horn button pushed, the horn sounds good

The current left side switch looks fairly new, clean with smooth operation, and the motorbike has always been stored indoors.... but that is all I can say about it

I DO NOT have a spare R75/6 Switch that I could try a plug-n-play-replacement,
but I do have a spare mid 80s switch if that may help.

I know that opening up that left side light switch probably should be next,
but BEFORE I BEGIN, I just gotta ask if anyone has some good thoughts on this?
__________________
When you have eliminated the impossible
whatever remains however improbable
must be the truth..
DustyOne is offline   Reply With Quote
Old 06-04-2014, 07:52 PM   #2
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 7,898
You don't mention a wiring diagram. They are in all of the manuals. You should have a Clymer's and/or a Hayne's manual. They have wiring diagrams in them.

I had a problem a couple of years ago putting a new wiring harness in my Hannigan fairing. I discovered how the headlight was wired. I got it hooked up backwards but it works. Without the diagram I wouldn't even have gotten this far.

It actually sounds like you may be missing the ground wire to the headlight connector.

Do you have a test light?



This is the basic tool needed for electrical diagnosis work. When the alligator clip is attached to ground the light will light when the pointy end touches a hot wire. Buy this tool at any hardware store or auto parts place. Can be had for less than $10.
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is online now   Reply With Quote
Old 06-04-2014, 08:36 PM   #3
DustyOne OP
Riding@6500' & up
 
DustyOne's Avatar
 
Joined: Oct 2006
Location: Shaken not stirred
Oddometer: 359
I do have a ground light....several in fact.
My favorite is an old 30 year old model.
I do use it frequently...I just had to add that little bit about the OLD light!

I can work my way through electrical, but AM NOT anywhere near an expert at it.

As to the light:
There are 2 brown wires attached to the headlight that run from the same ground line, and that little parking light DOES ILLUMINATE fine when the switch is turned on.....while the headlight low/high does not illuminate. So since that same line is attached both to the 3-prong headlight plug AND the parking light with a good clean connection, it must be a good ground.

Manuals:
I do have a Haynes airhead manuals with the wiring diagrams, and a Clymer is on the way........do you have a favorite one to use?
I also have a BING Manual, and some of those Chicago Tech BMW Manuals, but do not remember which

I need to locate THE SPECIFIC Wiring Diagram for THIS MOTORBIKE,
and I will check to make sure the lo & high lines from the switch are on the correct spot on the circuit board.

From there I will post up the results.
__________________
When you have eliminated the impossible
whatever remains however improbable
must be the truth..
DustyOne is offline   Reply With Quote
Old 06-04-2014, 09:07 PM   #4
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 7,898
The diagrams in the Hayne's manual should be good enough. I actually use an older manual, Clymer's I think from 1983, it has diagrams in color. But your bike should be covered by the 1975 diagrams.

If you end up taking the switch apart be careful there is a spring loaded part inside the switch that likes to fly away.
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is online now   Reply With Quote
Old 06-04-2014, 09:56 PM   #5
Bill Harris
Confirmed Curmudgeon
 
Bill Harris's Avatar
 
Joined: Sep 2008
Location: backwoods Alabama
Oddometer: 5,898
Start tracing wires. You've got a misconnection somewhere in the headlight circuit. There is a yellow-white wire from the left handlebar switch that isn't getting power from the main switch or the "headlight always on" circuit/relay. The green-red wire for the headlight momentary flash is apparently connected
since that function works.

Get a schematic and a test lamp and start tracing wires... no easy answer.

--Bill
__________________
'73 R60/5 Toaster
Luddite. Not just a philosophy, a way of life...
Bill Harris is offline   Reply With Quote
Old 06-05-2014, 08:58 PM   #6
DustyOne OP
Riding@6500' & up
 
DustyOne's Avatar
 
Joined: Oct 2006
Location: Shaken not stirred
Oddometer: 359
okay y'all
I have found a decent wire chart
got my tester
and polished my best reading glasses
BUT
have to go out of town for a couple days
SO
will hopefully get to get on this Sunday or Monday

Thank you for the great advice/pointers....will report back next week (hopefully)


.
__________________
When you have eliminated the impossible
whatever remains however improbable
must be the truth..
DustyOne is offline   Reply With Quote
Old 06-08-2014, 04:07 PM   #7
DustyOne OP
Riding@6500' & up
 
DustyOne's Avatar
 
Joined: Oct 2006
Location: Shaken not stirred
Oddometer: 359
I have studied the wire chart (in color)
and wrote out wire flow on my own from what I see inside the headlight
ignition switch
relay
circuit board
handlebar switch

and then matched them together...it seems that I have been wired using the UK ONLY wiring setup
there are slight differences in the wire colors for a few lines, but everything seems to flow as it should, where it should, and it should work

now.....doing the actual testing!
looks like it all is working good for the most part, EXCEPT
the lo beam AND the high beam as they should illuminate coming OUT OF the handlebar switch on the low when turned on, the high when switched to that position, however, the high-flash-to-pass DOES work fine

SO......it looks like I should open up that bugger of a handlebar switch:loll

maybe I should buy another switch just for backup
__________________
When you have eliminated the impossible
whatever remains however improbable
must be the truth..
DustyOne is offline   Reply With Quote
Old 06-08-2014, 07:32 PM   #8
Warin
Retired
 
Joined: Aug 2012
Oddometer: 1,519
Another switch?

The left switch that your looking at is the 'dipper switch' ? ... it only changes hi beam to low beam and back again .. it does not turn on the headlamp .. that is on the ignition switch .. at least according to the Haynes wiring diagram I'm looking at .. you need to look at that as it supplies the power to the left dipper switch (and then on to the headlight) ... it should also supply power to the tail light and instrument lights. If the tail lamp and instrument lights are working then you can start looking at that left dipper switch? Arrr a '75 .. theres a relay in there too.

The 'flash' switch works because it does not get its power from the ignition switches 'headlight' position.

-----------------
So .. more information - Do the tail light and instrument lights work?
If not then its the light switch/relay .. not the left dipper switch.
If they do then you can think about the dipper switch.

Warin screwed with this post 06-08-2014 at 07:44 PM
Warin is offline   Reply With Quote
Old 06-20-2014, 03:57 PM   #9
DustyOne OP
Riding@6500' & up
 
DustyOne's Avatar
 
Joined: Oct 2006
Location: Shaken not stirred
Oddometer: 359
yes, the taillight works fine, kind of hard to see the instrument lights, but will give it a check in the garage this evening.

so.....I have opened up that left switch, and it appears all wire solder connections are intact.
I am staring at "the C-clip" that holds it together, fingers twitching but not shaking....yet!

I must ask this before I slip the clip:
At this point, the ONLY 2 things this can be are either
1.) the left switch....or
2.) that relay inside the headlight that all of this stuff we are discussing goes through.
............correct????

I DO NOT WANT to toss that switches guts all over the place unless it is the last option.

Would it make sense to TRY A DIFFERENT RELAY first?

Would it just be the standard type 12V relay with the same number of connections, OR would the Special-BMW-Relay be needed?
__________________
When you have eliminated the impossible
whatever remains however improbable
must be the truth..
DustyOne is offline   Reply With Quote
Old 06-20-2014, 09:47 PM   #10
boxerboy81
Stay Horizontal
 
boxerboy81's Avatar
 
Joined: Jul 2009
Location: Melbourne, Oz
Oddometer: 2,073
Quote:
Originally Posted by DustyOne View Post
Would it make sense to TRY A DIFFERENT RELAY first?

Would it just be the standard type 12V relay with the same number of connections, OR would the Special-BMW-Relay be needed?

boxerboy81 screwed with this post 06-23-2014 at 07:09 AM
boxerboy81 is offline   Reply With Quote
Old 06-20-2014, 11:16 PM   #11
Warin
Retired
 
Joined: Aug 2012
Oddometer: 1,519
Quote:
Originally Posted by DustyOne View Post
yes, the taillight works fine,

Would it make sense to TRY A DIFFERENT RELAY first?
The relay should unplug .. using a bit of wire jumper the main contacts and see if that does the job?

If you want to be certain it is the switch you should be able to measure 12 volts in on one side ... and then (on either hi or low beam) 12 volts out. If there is no 12 volts anywhere on that switch ... then it is not the switch! Note the 12 volts is battery voltage .. it could be a little lower or higher .. does not matter as long as it is not close to 0.
Warin is offline   Reply With Quote
Old 06-21-2014, 04:12 AM   #12
Horsehockey
A GPS? Huh?
 
Joined: Nov 2010
Location: Vermont
Oddometer: 315
As noted above, it's either the headlight relay at fault or the left side handlebar switch. Overall, the success rate for disassembling and repairing the handlebar switch is very low. But I'd read this thread and see if the relay "clicks" when the switch is energized (with ignition switch on). When I had this issue years ago, I seem to remember wasting money on a new headlight relay only to find that I needed to replace the handlebar switch (that's a fun job involving about eight wires out and eight into the bucket). Been working fine since.

http://www.advrider.com/forums/showt...hlight=flasher

Horsehockey screwed with this post 06-21-2014 at 04:25 AM
Horsehockey is offline   Reply With Quote
Old 06-21-2014, 05:25 PM   #13
DustyOne OP
Riding@6500' & up
 
DustyOne's Avatar
 
Joined: Oct 2006
Location: Shaken not stirred
Oddometer: 359
okay now, on the left handlebar switch, I have power going in on the GREEN Wire, but NOTHING going out.

I can see the headlight flasher lines work, but NOTHING for the LOW & HIGH BEAM Wires.

I do have a donor switch from an early 80s RT that I can try.
It does have -9- Wires dangling from it, but it is because of the BLINKERS on that side. Shoot.....maybe if it is a GOOD SWITCH (as it was advertised) I will just hook-up the blinkers FROM THE LEFT SIDE and drop that funky one on the RIGHT....push up ---> push the right bar -----> and then turn right following the flasher. Then the LEFT TURN SIGNAL.....xxxxx...xxx.x.xx.x.xxx

BMW TURN SIGNAL SWITCHES....I DO like the ones I had on my 99 R1100S with the paddle for each side.....push the paddle.....turn that direction....then push up on the cancel switch. Once you really got the hang of it and got in "the rythym" it worked quite well IMO.

But I guess I can live with that 80s slide left....slide right...slide back to center to cancel.....ANYTHING IS BETTER than the R75/6 turn signal switch

Thank y'all for the help thus far, hope tomorrow I can slay that dragon
__________________
When you have eliminated the impossible
whatever remains however improbable
must be the truth..
DustyOne is offline   Reply With Quote
Old 06-23-2014, 02:56 PM   #14
DustyOne OP
Riding@6500' & up
 
DustyOne's Avatar
 
Joined: Oct 2006
Location: Shaken not stirred
Oddometer: 359
I am STILL LOOKING, now it is off to the light relay

I am checking this "Light-Relay" and have 2 questions concerning when the key and power is applied to the relay:

1.) I do not hear any click, nor does any sound come from it
2.) on the 87 connector, there IS NOT any power coming out from it and into the YELLOW WIRE that then heads up to the left handlebar switch

Isn't the "87" supposed to be HOT once the key is turned on?
__________________
When you have eliminated the impossible
whatever remains however improbable
must be the truth..
DustyOne is offline   Reply With Quote
Old 06-23-2014, 03:32 PM   #15
DustyOne OP
Riding@6500' & up
 
DustyOne's Avatar
 
Joined: Oct 2006
Location: Shaken not stirred
Oddometer: 359
Wicked One more indicator

sorry about this, did not notice it before....BUT:

key on 1st position, which is the parking light, the background lights for the clocks all light up

then when switched to the 2nd position, the run mode, THE BACKGROUND LIGHTS for the clocks BOTH GO OUT, but the colored center lights for neutral, gen, and oil light up

also when the key is in this position, when I flip the flash-to-pass high-beam, I also get that high-beam light to light up-blue (it is inside of the tach unit)


thoughts....ideas.....time to buy a new relay??
__________________
When you have eliminated the impossible
whatever remains however improbable
must be the truth..
DustyOne is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 06:51 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014