Headlight Wiring Woes

[hudson]

Jean - I understand what you are saying. The new main harness has those GR/BLK & GR/RD tracers that go back there, but there is also both a BRWN and a BLK/White ( I think originally gray/blk) tracers as well. There are also BL/BLK & BL/RD. Not sure what they go to, but they attach to some wire harness back there. You are not wrong, I am on the same page, I guess I am calling it something its not. Anyway, there are 6 different color wires that come out of the end of the main harness to plug into brake lights & turn signals. These were hooked up successfully. I really appreciate your time responding.

[Jean]

OK, In case I didn't say it before, BROWN is GROUND...and all the lights, etc. have a dedicated ground wire. Ground does not depend on the metal frame for "out-lyers" to be grounded! The blue-black goes to the RH blinker and the Blue-red goes to the LH blinker and each one of them also has a Brown wire. The Tail light and Brake-light share the main Brown in the harness. They might be all connected together, or they might be connected to the metal shell of the tail/brake light.

The wire you are calling "white" is probably GREY...A Grey-Black wire DOES go to the tail light!!
Compare the background color to a REALLY White wire and it'll probably look grey.
Yes, it's hard to tell the difference sometimes, especially with an old White wire and a new Grey wire.

I get hanks of wire of the correct colors from my nearby, friendly VW wrecking yard, when serious repairs are necessary!!

[Flatwins]

I still need to read through this thread in it's entirety but I wish I was closer to you and could take a look at it. The /5 is fairly simple (it has to be for me to understand since I'm no electrical genius). FWIW, the /5 ignitions switch is different from the later models since it also included the headlight on\off switch.

[Jean]

The Haynes manual shows the alternate wiring for the US versions and the rest of the world (headlight switch) even on the newer bikes. It appears up to around 1980, the DIN color coding was the same.
With the intro of electronic stuff and computer controls, wiring got weird.
the /5 and (up to) my 78s seem to be all the same.
Be gentle with an OEM /5 ignition/headlight switch. there's a LOT of wires in a tight space!!

[hudson]

Ok everyone - just wanted to give an update: I have everthing working except two things - the horn and the 2 speedo unit illum. bulbs to light it up when its dark out. So I am going back to retrace since it needs power and evidently is not getting it. Almost done! Ordered new bulbs and bulb sockets from Hans @ Hucky's Bmw.

Again - Thanks everyone for your patience and help!

[Jean]

Consider ADDING A RELAY someplace for the horn.
Horns draw a LOT of current and have been responsible for a number of smoke releases in wiring harnesses and headlight shells.
(electrical education: Horns and starters run on SMOKE. When the smoke escapes, the thing fails to function. did you know that?)

[hudson]

Jean - appreciate the advice as to the horn relay. Since I know nothing about wiring/electrical really, I wouldn't know what model/specs to get. Any input on this?

R u serious about the smoke thing? It sounds funny and since I know next nothing about my newly obtained beemer, I will be totally gullable.

[hudson]

actually 3 things are not working:

1) Neutral light bulb indicator. And yes, the blue wire is connected in the main harness to the back of the tranny.
2) the two illumination bulbs that light up the speedo unit
3) the horn.

I am puzzled by the bulbs - even when I hook up to direct power they still don't work. Then I thought maybe the socket was bad. I connected socket in question to wires/socket unit that is working (ie oil indicator). Exchanging bulbs as well. No deal...

Any ideas?

I am so close fellas!

[Airbear]

R u serious about the smoke thing? It sounds funny and since I know next nothing about my newly obtained beemer, I will be totally gullable.

Hudson, Jean is dead serious about the smoke. If any smoke escapes from your wiring it needs to be replaced.
Check this
http://www.google.com.au/imgres?imgurl= ... CCEQ9QEwAg

I don't know the part number for Bosch replacement smoke. I got a big drum of it years ago - a lifetime supply. Can anyone help?

ps: re bulbs - get yerself a pack of them from your local auto-electrical shoppe. You'll probably need them along the way.

[Jean]

If you KNOW the actual LAMPS are good, the problem is probably an inadequate ground connecting the little (AND they ARE LITTLE!) sockets.
It is possible all 3 of the lamps are shot, though.
Did they work before the untimely end of your wiring harness inside the shell?
If they DID, probably something got disconnected.
Normally, one lead comes off the common lead to the headlamp for the speedo lamps. The neutral lamp is fed from an independent "switched-power" lead since you want it to light in both day and night, but only when the switch is ON.
They all seem to share a ground, however, so that is what makes the ground the primary suspect.

We are sorta pulling yer leg about the smoke, but you DID already observe that escaping smoke was detrimental to operation of most things electrical, din' you?

PS. Have you got a multi-meter?