Broken Blinkers?

[RMBaiada]

Both my blinkers do not work. The hazard lights, as well as the high-low beam function on the stalk, both work fine, but not the blinkers.

 

I am just finishing installing the wiring harness on my 1974 BMW 2002 (VIN: 4223665), and I got everything else working except the blinkers.

 

I tried to chase the wiring from the wiring diagram, but I need a wiring diagram or a picture of the inside of the blinker switch. Is that available?

 

My assumptions are that:

 

1. Since both L and R blinkers don't work, I am assuming that I missed a connector someplace, but I don't see it.

2. Since the hazard lights work, I assume that it is not a flasher, bad wiring or light bulb problem.

3. I was told that the relay under the steering column was part of the buzzer (see pics below) with 2 wires hanging loose that I can't find spots for, but I am not so sure. Why would the buzzer need a relay?

 

Finally, it would be nice to see a much more detailed wiring diagram if that exists.

 

 

[Vicleonardo1]

Have you checked your fuses?

[Mark92131]

1 hour ago, RMBaiada said:

Why would the buzzer need a relay?

 

It doesn't need a relay.  The buzzer is plugged into a connector.  One wire Brown/Green is suppose to connect to a contact on your ignition switch (key in + door open contacts?), the other wire Red/White connects into the 9 pole connector for your turn signal switch. It doesn't look like your wires match up for a 1974.  You might try looking at the wiring diagram for a 1975, it had key-in, door open contacts and seat belt interlock connections linking to that buzzer.

 

Mark92131

 

http://www.2002tii.org/diagrams/bmw2002-usa-1975.pdf

 

Open this diagram in Adobe to see the component reference table

 

 

[RMBaiada]

Both fuse #6 (blinkers) and fuse #2 (hazard lights) are good, have power to them and continuity across the terminals. 

[RMBaiada]

Mark,

 

I am using the Prospero's Garage color wiring diagram (see attached), that is supposed to go from 1973 forward.

 

If the relay under the steering column is not for the buzzer (pictures above), any idea what it is for?

 

Also, the plug from my turn signal switch is an 8 pole plug, with 6 slots used and 2 slots not used. 

BMW 2002 Color Wiring Diagram.pdf

[Son of Marty]

Why would the buzzer need a relay?

 

Why does a 02 need the buzzer at all, you need that key to lock the door anyway?

[Mark92131]

24 minutes ago, RMBaiada said:

I am using the Prospero's Garage color wiring diagram (see attached), that is supposed to go from 1973 forward.

 

Beautiful work, but pretty generic, covers both Tii and non-Tii cars.  The 75 Wiring Diagram attached lines up with your situation better.  The turn signal connector #59 has 8 plugs, 6 used, 2 open.  The buzzer #94, plugs into connector #95 (which I think you are identifying as a relay).  Check the wires coming out of the relay, what color codes are they?  Use Adobe reader to open the PDF so you can see the component table.  Does your car have interlock seat belt connections under the seat?

 

Mark92131

 

 

bmw2002-usa-1975.pdf

[RMBaiada]

Mark,

 

Thank you. This helps, as I can see much more detail, and hopefully I can trace the circuit. But it will take some study and good glasses.

 

Michael

[John_in_VA]

Are your turn signals installed in the fenders?  They need the screws to ground the circuit.

[RMBaiada]

The hazard flashers all work, so the bulbs, ground and wiring to each of the four corners is good.

[Mike Self]

Two more thoughts:

1. Your turn signals work only with the ignition on, while the emergency flashers work regardless of whether the ignition is on or off.  That's the reason behind all those wires emerging from the emergency flasher switch.  Internally the switch has two sets of contacts:  one to power the emergency flashers and the other to allow the turn signals to work, but only with the ignition on.  I've had experience with those switches where they didn't provide power to either the turn signal circuit or the flasher circuit.  If you have or can borrow a spare switch, try substituting and see if that solves the problem.  If so, the switches are available new, or if you want to try repairing yours, PM me as I did a column on this very subject last year.  
2. The other thing to check is the turn signal switch itself.  They can get gummed up internally or even break.  In that situation the emergency flashers would still function, but not the turn signals...

 

mike

[RMBaiada]

Success.  With Mark's much more detailed wiring diagram and Mike's input about the hazard switch, I was able to trace the fault to the hazard switch. It seems that with the button out, the hazard lights worked fine, but with the button in, it had to be jiggled just right to connect the switched power source and allow the blinker stalk to work.

 

What I found out was that the flasher flashes any time there is power through the flasher. If the hazard switch works, all the blinker stalk does is connect the blinkers to the power source through the flasher.

 

What through me off was that I had 2 hazard switches with the same fault.

 

Thank you all.

 

Michael 

Edited May 1, 2020 by RMBaiada