Still got wiper probs on '98 E39

Still got problems with these bloody wipers...

Changed the relay K11 (only one relay on '98 model, not 2 as in earlier
models) - is this the only relay in the wiper circuit ?

Checked the wiper mechanism and it seems OK, moved freely manually.

Checked voltage on wiper motor, only getting 2.6v across Brown and
Brown/Black. Strangely still get this when the key is out of ignition.
Should you get full 12v to operate motor. Does the 12v get switched directly
from K11 relay ?

Symptom now is either wiper don't operate, or they will operate temporarily
( couple of seconds) with a juddering motion.

Model is 1998 E39 523SE

Scott wrote:
> Still got problems with these bloody wipers...
>
> Changed the relay K11 (only one relay on '98 model, not 2 as in
earlier
> models) - is this the only relay in the wiper circuit ?


My diagram shows Stage I and Stage II relays but the K11 may
incorporate both sets of circuits in one unit.


>
> Checked the wiper mechanism and it seems OK, moved freely manually.
>
> Checked voltage on wiper motor, only getting 2.6v across Brown and
> Brown/Black. Strangely still get this when the key is out of
ignition.
> Should you get full 12v to operate motor. Does the 12v get switched
directly
> from K11 relay ?
>

The constant power comes from "KL 30 battery bus" to Stage I relay. I
don't know how the KL 30 works but if it's a common bus perhaps it
should be 12v.

The K11 gets power (via the KL 30?) from a 30A fuse (F1) along a
Red/White 2.5 sq. mm wire that is in turn connected to the 80A F110
fuse (somewhere in or behind Fuse Panel 1, glove compartment). The
same F110 fuse apparently powers F1 through F5. You want to check F1
in Panel 1 and make sure it's correct (and supplying 12v?).

The Black/Brown (pin 3) on the K11 is for fast speed but there is also
a Black/Green (pin 2) for slow speed. The Brown wire goes from the K11
to ground. I would look for and check the Black/Green as well and
maybe set wiper at different speeds during test. Both the Black/Brown
and the Black/Green originate from K11 (pins 6 and 4 respectively) and
are of similar gauge 2.5 sq mm wire.


> Symptom now is either wiper don't operate, or they will operate
temporarily
> ( couple of seconds) with a juddering motion.
>
> Model is 1998 E39 523SE