Re: 02 Turn Signal Question

[Zenon Holtz <zholtz@xxxxxxxxx>]

Hi Kris,

When the dash indicator does not work or works intermittently that is a
sign of either burnt-out or wrong wattage bulbs or bad electrical contacts
or grounds leading to low current draw. If there is not enough current
being drawn by the lamps, the indicator is not activated - this is a design
feature so that you will be warned of burned out or dim turn signals. It is
almost never a due to a problem with the flasher unit, column switch, or
the wiring itself.

Before suspecting anything else, first check that the bulbs are good
(obvious, but often neglected). If so, make sure they are well seated in
their fixtures, the bulb bases and fixture contacts are clean, and that the
grounds to the fixtures are good. When buying replacement bulbs, try to get
Osram brand bulbs with nickel plated bases. Cheaper plain brass base bulbs
are more prone to corrosion and will cause more trouble. Osram is high
quality and OE for BMW. If the bulbs are old and darkened but still work,
replace them anyway.

The front turn signal fixtures are notoriously bad and are usually the
problem. Typically, the area of the fender where they are mounted is rusty,
leading to bad grounding. They ground through the screws that hold the
fixture to the fender. It may ultimately be necessary to add a ground wire
from the inner frame of the fixture to a clean, solid ground point on the
inner fender. Note that if you are testing the system when you have the
turn signal assembly unscrewed from the car, nothing will work unless you
run a jumper lead to ground (duhhh, been there).  Sometimes, the springy
contacts at the bottom of the bulb socket get loose or corroded or bent. 

Very commonly, the wires to the fixture get reversed so that the low power
filament of the dual filament bulb (21W/5W) is used for the turn signal
rather than the running lights. If you have very bright running lights and
dim turn signals, there's your problem.

In the rear, make sure the bulb is a 21 watt unit and not a 5 watt one.
Again, check all the connections. Look carefully at the grounding points in
the trunk - you will have to remove the trunk floor panel. On german cars,
ground wires are always brown.

If, in the end you determine that all is well and it really is the turn
signal flasher relay, then you can use a standard, generic, $5,
three-terminal round relay from the local Schucks. 

I can give more detail if needed but you can carefully free the spade
connectors from the plastic connector block of the original flasher,
leaving the brown ground one in place (it is not needed for the generic
flasher).  The stock metal connectors will fit right onto the generic
flasher unit - you do not have to cut or splice a single wire, this is
completely reversable if done carfully.  Use some electrical tape to
insulate the bare connectors.

The three terminals look like this:

 | _ | 

from the bottom of the generic flasher, the two parallel ones are the
"input" and "output" while the third terminal is for the indicator lamp (if
i remember right). The black/white wire (dash indicator) goes to the center
third terminal, the green/violet (power in) and green/yellow (to
switch/lamps) wires go to the parallel terminals. It's been a while so I
may be off on the connections - I originally figured this out by trial and
error. 

With the turn signal switch set to left or right (doesn't matter) and the
key on, the yellow/violet wire will have power to it. There are only few
combinations, if you get them wrong nothing bad happens - you may have dash
indicator but no signals, dash indicator on all the time, nothing, or it
works right. If anyone is really interested I can go out to my car and
actually look at the setup ;-)  I hate removing the under-dash panels!!!
Anyway, there is no need to spend $20 to $40 for a new flasher unit.
 
Hope all this actually helps. 

Regards,
Zenon

>Date: Thu, 10 Sep 1998 12:57:40 -0500
>From: Kris Ackerbauer <ktackerbauer@domain.elided>
>Subject: 02 Turn Signal Question
>
>I've got a '73 02.  When you use the right turn signal, the indicator on
>the dash flashes once or twice and stops,  the actual signals continue
>to work normally until the turn is complete.
>
>The left signal and indicator flash normally.  The hazard lights all
>flash normally.

Zenon Holtz, zholtz@domain.elided
1.5x '73 BMW 2002
Secretary/Treasurer - BC 2002 Club

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