Electrical "Issues"

[Bob_Roller]

Mike, I'm not real sure, I know there are two connectors for the wires coming out of the top of the engine, one is for the ignition 'beancan' should have three wires, and the other is for wire(s) for the alternator voltage control, the light blue wire that is visible .

[Red_Hen]

I just need to get into my "zone" to figure this out.  Maybe watch the old Karate Kid a few times.

Will kee you posted and THANKS for being willing to help!

[Mike V]

Ken,
Take my recommendations with a grain of salt, I suck at this electrical stuff - an Italian trying to solve German electronics = another war lost.

Do you have a clutch switch on your bike? I believe there's a connection from the clutch switch at the bar that goes directly to your starter relay, maybe not applicable on your bike. I'm going to gracefully bow out while I still have a shred of dignity.

[k_enn]

If you think it is a starter or starter relay issue, check out the thread on Starter Troubleshooting.  (Sorry, I don't know how to link to it).  The thread began on 4/26/10 and the last post in that thread was on 5/1/10.  The thread contained some great advice on how to check out the starter relay.  You should be able to easily determine from that thread if it is the relay, the starter, or something else.

PS, just because a relay or connection looks good does not mean that it is good.   My problem at the starter relay has resurfaced.   The relay looks fine, and the connectors have been cleaned and look good.  Upon further testing, I have cause to question the relay (it recently took several applications of current directly to the appropriate connection points with jumpre wires before the relay closed the contact).  

k_enn

[Red_Hen]

Okay - spent better part of the afternoon removing contacts, cleaning, reattaching - diode board, alternator connectors . . . tried Bob Roller's suggestion to bypass the kill switch - NO LUCK

Now, what if the ground wire I've been attaching to the negative post isn't THE ground wire?  Although it is black, I've just looked under the black protective sheath and see it's red - dmaybe this is the solenoid wire that goes to the positive instead of negative pole?  No, that doesn't sound right.

I'm pretty much out of ideas short of replacing the wiring harness - I've really gone through it - BUT only to the best of my skill set.  

Attached pictures: 1st pic is the heavy wire I've got attached to the positive terminal on battery.
2nd pic shows a black sheath over a red wire - that's on the negative terminal.  I've also got a black wire attached to the engine connected to the negative terminal.

Wouldn't it be simple if the terminals were reversed? - way too simple.

[Bob_Roller]

Just so we don't miss something simple, the negative cable from the negative post of the battery is bolted to the transmission case at the speedometer drive area .

There is another wire, that should be on the positive post of the battery besides the large diameter cable, that wire feeds electrical power to all of the electrical systems on the bike .

I think you have it on the wrong battery terminal .

Two wires on the positive post, one on the negative post .

I think you've gotten to the problem here !!!!!

[Red_Hen]

I think so!
will give it a go & let you know

[Red_Hen]

Okay - problem partially solved.

Had the second hot wire on the negative side of the battery.  Now have electricity.  I can't friggin believe it.  I'm so happy.  Horn works, light works, dash lights work, turn signal works!!!

Must be in gear because starter switch doesn't turn over - will try it on a charger.  Must be in gear.  

I AM SOOOOOOOO Excited!!!!!  

Thanks!  

Now on to the next process of getting bike started!!!!

Thanks  Thanks  Thanks

[Bob_Roller]

GREAT !!!!!

Time for a cold one !!!!

[Red_Hen]

I understand where the ground wire connects (on the bolt that holds the speedo cable).  What gauge wire should I use?  My bike didn't have a ground wire when I acquired her.

Now that I got the electrics to work - last night when I pressed the starter button, all I hear is a click - so I put the trickle charger on last night - horns, t/s, brake lights work. If I want to jump the starter with a screwdriver, which terminals to I touch the screwdriver on?

Bright lights work but low beam won't stay on.  

At this point, I'll have to play with connectors attaching to my new ignition switch- when from off to the first click, both instrument red lights come on - thinking that should be the parking light only on the tail lamp.  Will have to play around.

[Bob_Roller]

If you don't have a heavy gauge ground wire connected from the battery to the transmission, the starter will not work .

The starter is grounded to the engine case through the metal case of the starter .

If you don't have a complete circuit, the starter won't have any electrical flow .

Just taking a look at some wire samples here at work my guess is around AWG 4 or 5 gauge cable, AWG stands for American Wire Gauge, I think it's based on drill bit diameter size, but not real sure .

Someone here posted that they went to a local auto parts store, and found pre-made cables that worked fine on their bike .

If you happen to be around one in your daily travels stop in and see what they have .

[Red_Hen]

Thanks Bob - where do you suggest I attach the ground wire to on the bike?

[Bob_Roller]

The ground cable is secured by the bolt that holds the speedometer drive cable to the transmission .

The bolt needs to be a hollow, or drilled bolt, it is the atmospheric vent for the transmission as well .

Of course a BMW only part !

[Red_Hen]

Of course!

[montmil]

Someone here posted that they went to a local auto parts store, and found pre-made cables that worked fine on their bike .

Most FLAPS have them in pre-made lengths. Or NAPA will make up a to-your-specs length battery ground cable, in black, for a very nominal cost. That's where I got mine for the '81.

For the '83, I made up my own using a DIY swaging tool and terminals n' cable from Ace Hardware and BMW Supply. [smiley=thumbup.gif]

P.S. And don't feel too bad, Ken. You're not the first to mis-wire something.
I had to drive to Austin, Texas only to discover that both my rocket scientist sons could not figure out why the riding mower would, as they said, "crank" but not fire. Those boys! They had installed a new battery but crossed wired the cables. The starter was running backwards and would not engage the flywheel gears. D'oh! I'm surprised it had not fried something. But it fired up and ran for years.

Monte