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Strange Electrical Problem

Started by DLW, September 02, 2007, 07:55:51 AM

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DLW

Yesterday I decided to clean up what I could of my '92 since I finally got it plated and registered.  Figured since I could legally take it out on the street I might wanna make it look good, considering what I have to work with.

So I started on the wiring up front as the PO had done a crappy job of some electrical tape work.  I believe the PO kept it outside as it had just nasty crap all over it.  So I pulled some tape off...retaped, pulled the headlight apart and cleaned up in there "some" and pulled out a dead moth, etc.  Retaped everthing back up and to clean the wires I sprayed some WD40 on a shop towel and rubbed the wires down.  Did a nice job. 

Once I got it all back together, I tried to start it.  NOTHING.  I had all my lights/dash/signals/yes even the horn but NOTHING at the start button.  I did a frantic search here for 2 hours.  Running up and down stairs(my computer is upstairs) trying different things.  I jumped the starter/relay and it started up so I knew it was something electrical back to the relay(correct?). 

Well when I was pulling tape apart to retape I noticed that the clutch switch wire covering had been sliced open and the two wires inside were exposed and then shorted across.  So I, being as diligent as I could be, fixed this problem thinking that that can't be good.  Well after 6 hours of fiddling with it last night and checking and rechecking my tape job and all the connections.  THAT was the problem.  Turns out those two wires being shorted across completed the circuit, thus allowing the start button to work.

Knowing all this, is it possible (which I believe it is), I have a short or problem somewhere else in the starting circuit?  If so any thoughts on what I should check?

Thanks muchly in advance for any thoughts or advice on this subject.

DLW

P.S.  While writing this I had an idea, is it possible that my clutch switch is bad since shorting those wires across fixed it??

92 GS500E - '89 clip-ons, '04 signals and rear fender(pending 'ectomy), new dash and gauge buckets.

beRto

Normally, the bike will not start unless the clutch lever is pulled in.  It sounds like the PO sidestepped this by shorting out the switch in the clutch lever.  I don't think this will do any damage to your starting circuit, but if you want to return the electrical system to stock (i.e. restore this important safety feature), you will have to repair the clutch switch.

Depending on the mod, you willl either have to undo the shorting-mechanism the PO installed (although you suggest this didn't work), or replace the clutch switch altogether.

DLW

Correct.  I did try to correct what the PO did.  By separating the wires and taping them apart.  Didn't work.  Even tried pulling in the clutch.  I've never had to pull the clutch in to start it.  EVER.

However, shorting those two wires across.  Worked just like before.

DLW

92 GS500E - '89 clip-ons, '04 signals and rear fender(pending 'ectomy), new dash and gauge buckets.

beRto

QuoteI've never had to pull the clutch in to start it.  EVER.
You never had to pull the clutch lever in because the switch had been shorted out.

QuoteHowever, shorting those two wires across.  Worked just like before.
Of course.  You have simply bypassed this safety feature also.

QuoteI did try to correct what the PO did.  By separating the wires and taping them apart.  Didn't work.  Even tried pulling in the clutch. 
The previous owner probably dismanted the switch to gain access to the wires and allow him/her to short them out.  I suspect you cannot simply tape them apart, you'd have to re-install the wires in their original positions.  However, this may not even be possible; the switch may be irreversibly-damaged and require replacement.  Either way, I'd suggest you fix this because the clutch switch is an important safety interconnect.

Good luck.  Let us know how it turns out.

ohgood

Mine came with an alligator clip instead of the clutch interrupt. ;)

After a few thousand miles, I bypassed it. Yes, it will start in gear now. No, I don't really worry about it. If someone manages to gain access to my keys, well, a safety switch be damned. Let the topple it on their scrawny thieving legs.

I'm already in the habit of starting things only after checking for parking brake application, clutch disengagement, etc.

On a side note, the trucks clutch interlock switch was replaced (by me) for safety reasons. I really don't want anyone accidentally (myself included) running over small animals, children, adults, MY BIKE or anything by accidentally engaging the starter when all they really wanted was to listen to the radio. ;)




tt_four: "and believe me, BMW motorcycles are 50% metal, rubber and plastic, and 50% useless

starwalt

Sounds like your clutch switch went bad previous to your ownership and someone decided to bypass it. When you put it right, it reverted to the failed state.

There are at least two types of clutch switches for the GS, maybe three.

If you wish to revert to stock, as mentioned previously, simply replace or repair the switch.

This is an easy repair for someone who has gone as far into the wiring as you have.

I have a few pictures of the oldest style switch. Click the thumbnail for a bigger photo.


This one is bad because of a broken off square shaft that interfaces with the clutch handle. What should be existing is dotted-lined in the photo.

Newer units have more of a micro switch like the front brake.
-=Doug......   IT ≠ IQ.

God save us from LED turn signal mods!

Get an Ebay GS value  HERE.

1990 GS running, 1990 GS work-in-progress, 1990 basket case.
The trend here is entropy

DLW

Starwalt,

Mine looks just like the one you have pictured "with" the small square that you say is missing.  So I can't tell if my switch is actaully bad.  How could I test the switch?

DLW

92 GS500E - '89 clip-ons, '04 signals and rear fender(pending 'ectomy), new dash and gauge buckets.

sledge

DLW?
You have sarcasticly stated "somewhere else" that originally asking this question in here was a mistake? ......but now it seems your back wanting more help.  Do you not appreciate the time and effort Starwalt has taken  to help you out? If someone answers your question will you be going back to "the other place"  for another second opinion and another put-down....If not I will be happy to answer your question regarding continuity testing of the clutch switch, if you do go back and make more negative comments, you will be taking the pi** out of everyone in here and I wouldnt be surprized if people start to ignore your questions in future.

DLW

#8
Sorry Sledge but I don't feel that I have to justify my comments "elsewhere" to you.  You can help me if you like.  I'm just looking for help.  And if you had noticed I made that post "elsewhere" BEFORE Starwalt's post here.

Thank you Starwalt and others for your help and comments.  I do appreciate them.  I was just looking for a more rapid response.  Nothing more.

Sledge, if you feel that you need to go snooping "elsewhere" for ammo on this board.  I find that very sad. You can help me or not. That is your choice.

DLW

92 GS500E - '89 clip-ons, '04 signals and rear fender(pending 'ectomy), new dash and gauge buckets.

sledge

DLW?
The way I see it you made and, unwarrented and sarcastic attack on the people here who took time out to help you with your problem, and the excuse you have given is nothing short of what makes the grass grow tall in texas! Would you care to repeat in here the first paragraph of the other posting you made? the one that includes the comments..."I should have posted it here first" " I posted it on GStwin first...what a mistake" and "Consider it lesson learned"  and at the same time explain why you chose to use those terms if all you wanted was a quick answer?

Snooping on other forums may in your view be sad, but ungrateful comments and critisicing those in here who took time out to help you is ...well.....even sadder in my book.

I didnt contribute to your thread, to be honest I couldnt be bothered, your problem is common and very minor, its been covered many times and is easily put right and I was quite happy to let someone else do the talking. If I had chosen to comment and make an attempt to help you, right now I would be saying to you "Here is the finger, go swivel on it"


starwalt

Quote from: DLW on September 03, 2007, 08:20:55 PMMine looks just like the one you have pictured "with" the small square that you say is missing.  So I can't tell if my switch is actaully bad.  How could I test the switch?

You will, of course, have to reduce the switch assembly to something that looks like my (ancient) photo. If you don't know how to preform a continuity test - look THIS LINK over. The application is for the coils. You would be working in the headlight bucket and the clutch switch instead.  The value of resistance you are looking for is less than 2 ohms typically.

Warning: Some meters will display "0.0" ohms with an open circuit. Although 0 is less than 2, this does not mean your check is good. To see ideal, connect the two meter leads together and note the reading. This is what your goal is for a switch contact.

I will assume you have access to a VOM or DVM or even a simple "automotive" continuity tester. Use it to test the contacts of the clutch switch - they are seen in my photo on the elongated phenolic board as two copper strips - to the connector. The connectors inside the headlight bucket are of the "bullet" type - if memory serves me.  Just test from a contact to one of the wires coming from the clutch switch. The wires are Yellow/Green for both wires.  Don't confuse yourself and check from the switch to the harness side.

An alternative to using a continuity tester is - with the wiring put right - is simply shorting the two switch contacts together with an alligator clip. If the bike won't attempt to start, you definitely have a broken wire or poor connection.

The two clutch switch wires are opposite sex inside the wiring bucket. The typical by-pass involves disconnecting the switch wires and interconnecting the "bike side" wires of the harness. These should have insulation present on the harness side and should not have needed the dreaded black tape.

You could have a simple case of very dirty contacts. Use a pencil eraser to buff the two contacts on the board and the spring loaded, moving bit to shiny copper perfection. A electrically approved lubricant will prevent metal-metal wear that would reduce the life of the switch.

Don't be alarmed at anything you find in wiring harnesses. Good electrical practice seems to have been abandoned by civilized societies these days. Such is the results of nearly disposable electronics and MTV.  :laugh:

Give any of the above a try - we are very certain of the problem - and you will learn something new.  <temper, temper boys   :) >
-=Doug......   IT ≠ IQ.

God save us from LED turn signal mods!

Get an Ebay GS value  HERE.

1990 GS running, 1990 GS work-in-progress, 1990 basket case.
The trend here is entropy

DLW

Starwalt....thank you kindly for the info I will definitely give them a try and report back.

DLW

92 GS500E - '89 clip-ons, '04 signals and rear fender(pending 'ectomy), new dash and gauge buckets.

starwalt

It also occurred to me that you might want to view the wiring diagram for the bike.

CLICK HERE for a posted color diagram on Kerry's site. 
-=Doug......   IT ≠ IQ.

God save us from LED turn signal mods!

Get an Ebay GS value  HERE.

1990 GS running, 1990 GS work-in-progress, 1990 basket case.
The trend here is entropy

DLW

Quote from: starwalt on September 04, 2007, 02:33:56 PM
It also occurred to me that you might want to view the wiring diagram for the bike.

CLICK HERE for a posted color diagram on Kerry's site. 

Ya know...I have a clymer's that has the wiring diagram but that one that on Kerry's site is much nicer ;)  Thanks for the link!!   And all the help!!

DLW

92 GS500E - '89 clip-ons, '04 signals and rear fender(pending 'ectomy), new dash and gauge buckets.

starwalt

Kerry and I, as well as others, have beat the Clymer vs Haynes issue to death. I work on electronic systems for a living and still find the Clymer to be difficult to view.  On the other hand, I find the Haynes manual too simplisitic, but very good for the target audience.

Regarding your thank you - You are very welcome!

One day I am going to have to find time to work on an idea that 's been mulling around my head:

The GS Wiring Exposed - a web page that shows the entire wiring harness layed out like a high school dissection victim. Move the mouse over the section of wiring harness of interest and get a link to more detailed pics and information.

It would make a great FAQ item - any code monkeys wanna run with it?
-=Doug......   IT ≠ IQ.

God save us from LED turn signal mods!

Get an Ebay GS value  HERE.

1990 GS running, 1990 GS work-in-progress, 1990 basket case.
The trend here is entropy

starwalt

Here's another GSTwin thread regarding using a meter to check things....Kerry's excellent-as-always style.

CLICK HERE
-=Doug......   IT ≠ IQ.

God save us from LED turn signal mods!

Get an Ebay GS value  HERE.

1990 GS running, 1990 GS work-in-progress, 1990 basket case.
The trend here is entropy

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