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FAQ part 9/10
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Subject: FAQ part 9/10
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From: "Rick Kjeldsen" <fcmk@domain.elided>
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Date: Thu, 01 Dec 1994 16:20:42 -0500
Chapter 19.0: Electrical
Section 19.1: Fixing Automatic Antennas
A: (by Harvey Chao:Harvey_Chao@domain.elided)
If the automatic antenna you have doesn't (fully extend/retract when the
radio powers on/off) this may help you. The unit described herein is
factory original as installed on an '83 528e, and I expect
typical/standard over many years and models.
This is intended to address the situation where you can hear the antenna's
drive motor operate, but the mast fails to either fully extend or retract.
I suspect that many "failures" can be simply fixed, w/o purchase of parts
(new mast $35 -40) new antenna assembly ????. The following describes how
I fixed mine at no cost.
The first concern is that the mast itself moves freely, and is not
sticking because of dirt or gummed up old lubricant. Get the mast fully
extended, or remove it from the drive assembly, thoroughly clean, lube
lightly and be sure that the telescoping sections move freely, re-install
and or fully retract. The Bentley manual describes how to remove and
replace the mast. If it fails to fully retract, you can do this manually
by CAREFULLY pushing it STRAIGHT down. Be careful that you don't bend it!
Note that there is a retaining collar at the base of the antenna assembly
on top of the fender that has two flats (13mm if I remember) that unscrews
to facilitate removal and replacement of the mast. The mast itself is a
set of telescoping sections. Attached to the end of the topmost section
is a long nylon(?) flexible "cable", about .125" in dia. and maybe 3 '
long. This is the actual part that is driven by the motor/clutch assembly
to raise or lower the mast. Locate, remove the cover, expose and examine
the drive assembly. It is a box about 4x6x1.5 " with a black plastic
cover that is held in place by 4 Phillips head self tapping machine screws
into what appears to be a die cast aluminum or pot metal body.
Inside the box you should see the following basic arrangement. [I will
use the "clock" scheme to describe where the various major pieces are, 12
o'clock = top of the box, 3 o'clock = middle right hand side, etc.] The
drive motor is a metal cylinder, oriented long axis vertically located at
between 2 and 3 o'clock. It has a worm gear on its shaft that drives a
large plastic gear at the very bottom (or back) of a stack of various
disks, some of which freewheel on the shaft of the gear driven by the
motor, and some of which are "keyed" to that driven shaft.
On the opposite side from the motor, about 10 o'clock, you will see a
relay. coil on top, contacts on the bottom that pivot up and down from
one side. With the radio off and the mast retracted, if you use your
finger or a wooden stick to push the relay contacts closed (up), it will
actuate the motor. If you hold it that way, the motor will run until the
driven shaft described in the prior paragraph rotates a fixed number of
turns and the mast (if properly operating) will have been driven to full
extension. When you release the relay, the motor again actuates in the
opposite direction a fixed number of turns to retract the mast.
The largest and bottom disk on the driven shaft, looks like a pulley, is
just above the gear driven by the motor, and FREEWHEELS on the shaft. The
"flanges" of this pulley, along with a pinch roller located at about 7
o'clock grip the nylon cable and drive it up or down.
The next piece outward from the pulley is a clutch plate that drives the
pulley but also freewheels on the shaft. Next outward is the "pressure
plate" that is keyed to and driven by the shaft. What I think usually
happens, if the motor operates and the mast is free to extend and retract,
is that the clutch slips and thus the pulley doesn't turn enough rotations
to fully extend or retract the mast.
Next two pieces are spring "washers, very roughly star shaped, and convex,
assembled so that they provide some constant pressure against the pressure
plate and clutch assembly.
(editor's note: Use caution, this diagram may have been distorted!)
\\\\\\\\\\\ gear driven by motor worm gear
\_______________/
_______________ "pulley"
/ \
_____________ clutch plate
_____________ pressure plate
\____/ washer #1
____
/ \ washer # 2
________________
\ washer with lock tab
________________
I I Sheet metal nut.
Next outward from the second washer is a large flat washer with a tab that
is bent up to prevent "loosening or tightening" of the large sheet metal
nut that tops off this whole assembly. This washer is also keyed to the
shaft. The way this whole thing works is that the driven shaft transmits
torque through the clutch assembly to drive the "pulley" which in turn
drives the nylon cable up or down. If the clutch slips, the pulley
doesn't turn the required number of turns to drive the mast, but the
counting mechanism on the driven shaft does turn, and after the
predetermined number of rotations, stops the mechanism.
If you carefully use a screw driver to bend the locking tab back you can
free the large sheet metal nut (about 1.25 inches). Before you start to
move that nut, mark it in such a way that if you remove it, you can get
back to the original starting point. Then remove the nut, disassemble the
layers down to but NOT including the pulley. Use some solvent to clean
off the clutch face and pressure plate dry well, and re-assemble.
Starting with the mast fully retracted and the sheet metal nut in it's
original position, actuate the relay with your finger until the mechanism
"auto stops", release the relay and again let it run to "auto stop" so
that the mechanism runs through a full extend/retract cycle. If there is
still some slipping of the clutch and the mast does not fully extend and
or retract, push it down so that it is fully retracted, try tightening the
nut one flat more, and again actuate the relay to run through a full
extend/retract cycle. Repeat until you get proper cycling of the mast,
bend the lock tab up to lock the tension provided by the nut and button up
the cover.
==============================
Section 19.2: Taking care of your battery
A: (by Robert Moore:RMOORE@domain.elided)
Always used baking powder and water paste (the yellow box from Arm &
Hammer) followed by a thorough flushing with water. Let dry. Coat the
terminals with vaseline. I've NEVER had corrossion of the terminals
or connectors in 30 years.
I did once try a heavy grease. At underhood temperatures it turned into
something reminiscent of the stuff that comes out of an electric glue
gun. Forget it. Vaseline.
==============================
Section 19.3: Troubleshooting Central Locking System
A: (by Jim Conforti:jec@domain.elided)
Start with doors unlocked and all windows open
NOTE: NEVER CONNECT OR DISCONNECT THE CONTROL UNIT UNLESS BATTERY POWER IS
REMOVED!!
Operation Response Action
1 DDL to lock All doors lock Goto OP #2
Some doors Lock R/R suspect Door Lock Motor ckt.
No doors Lock Goto OP #4
2. DDL to deadbolt All doors double lock Goto OP #3
Drivers and SOME others dbl lock R/R suspect Door Lock Motor
Drivers ONLY dbl locks Perform TEST B
Drivers does NOT dbl lock Mechanical Problem
3. DDL to unlock All doors unlock Goto OP #4
Some doors unlock R/R suspect Door Lock Motor ckt.
No doors unlock Goto OP #5
4. PDL to lock All doors lock If doors did not lock in OP #1 R/R
DD lock switch
else Goto OP #5
Some doors lock R/R suspect Door Lock Motor ckt
No doors lock If doors locked in OP #1 R/R PD microswitch
if doors did not lock in OP #1 perform TEST A
5. PDL to lock All doors unlock If doors did not unlock in
OP #3 R/R DD lock switch
else Goto OP #6
Some doors unlock R/R suspect Door Lock Motor No doors unlock If
doors unlocked in OP #3 R/R PD Lock Switch
if doors did not unlock in OP #3 perform TEST C
6. Get in car, close/lock all Doors remain locked Goto OP #7
doors, IGN to RUN Doors Unlock R/R Central Locking control unit
7. Get out, DDL to lock All doors can be unlocked Goto OP #8
Unlock each door by All doors remain secure Disconnect connector from
control unit and check
pulling up button for short to ground at terminal #11
if short, find it!, if not R/R Control Unit
8. Trunk lock to LOCK Trunk Locks Goto OP #9
Trunk does not lock If doors lock, R/R Trunk lock motor and/or circuit
If doors do not lock R/R Trunck lock switch
R/R Control Unit if switch and circuit are OK
9. Trunk lock to UNLOCK Trunk unlocks Goto OP #10
Trunk does not unlock If doors unlock, R/R Trunk lock motor and/or circuit
If doors do not unlock, R/R Trunk lock switch
R/R Control Unit if switch and circuit are OK
10. Turn key back to LOCK Gas filler locks Goto OP #11
Gas filler does not lock R/R Gas Filler Motor ckt.
11. Turn key to unlock Gas filler unlocks Done, No faults!
Gas filler does not unlock R/R Gas Filler Motor ckt.
TEST A.
Measure Voltage at Control Unit Connector w/ Control Unit Connected
Term 3 and Ground should be battery, else check wire to Term 3 for open
Term 3 & 4 should be battery, else check wire from Term 4 for open to
ground
Jumper between Term 7 and ground, if doors lock R/R switches and related
wiring else ...
Disc. battery, remove Control Unit and reconnect Batt. jumper 1 & 3
together, now jumper 2 & 4 together if doors lock, R/R Control unit, else
check wires on Term. 1 & 3 for opens (see schematic)
TEST B.
With Conrol Unit connected, jumper between 10 & ground doors should double
lock, if not, check wires to Term. 11 for opens and R/R Control Unit if no
opens found. If doors DO double lock, check wires to Term 10 for open and
R/R Unlock Inhibit Switch if wire OK.
TEST C
With Control Unit connected, Jumper 6 & ground. If doors unlock, R/R
switches and related wiring (see schematic) if doors do NOT unlock R/R
Control Unit
==============================
Section 19.4: Jerky Wipers??
Your wiper motor has a bit too much grease in it and it has hardened up on
the "park" contacts in it. Sounds complicated, but it's actually (as far as
BMW's go) not TOO hard to fix.
The story is: the wiper motor has contacts in it that make it continue to
run, and park. These contacts close on a metal segment on the plastic gear
that drives the shaft coming out of the motor (the motor itself is at right
angles to this). If the housing had too much grease in it (which was fairly
common, at least on my year), or the grease has hardened up.. the contact
tend to skip a bit, causing the jerky action. The big hint is that it only
occurs in the intermittent mode (which you describe).
TO FIX (Two choices):
1. Go to dealer, sell left arm, buy new motor.
2. Remove motor and clean out grease, regrease.
ssuming you may want to tackle #2.. here is how it's done:
1. Remove the motor. I'd disconnect the power connector going to it first
(it will try to park otherwise if you accidently rotate it, perhaps taking
a finger or two with it). On my 535 - it's behind the cowling for the
fresh-air intake for the heater - don't have a clue where for a 3er..
remove the nut (and washer) holding the linkage to the motor, try to
prevent it from turning while you remove it. The arm connecting to it is
splined, but removes fairly easily (a good tug). Remove nuts/bolts holding
motor in vehicle. Walk it to your workbench.
2. Disassemble: The contact you want are behind the light aluminum plate
that covers the big gear (this will be fairly obvious).. on mine, the plate
was held on with mashed over aluminum studs. Right next to these studs were
holes through the plate and corresponding holes into the housing.. sorta
looked like these could be tapped to take a few screws for reassembly
(CLUE!).
3. Repair it: Drill off the mashed over aluminum heads of the studs (1/4"
bit works fine). The cover should remove easily. You'll find lots of nice
brownish grease. Clean the contacts (attached to the cover) and the face of
the gear where the metal segment is). Regrease lightly with a white lithium
grease (at least that's what I used)..very lightly!
While apart - tap the holes in the aluminum housing - I *think* I used 4-40
American (looked about right, and I had the tap and some short 4-40 screws,
but it might have been 2-56). Try to keep tap filings out of the housing
(grease on the tap helps a lot).
4. Reassemble: Put the cover back like you found it and screw it back
together. Reinstall motor in car. Align the motor by starting it once
WITHOUT the wiper arm attached and letting it go to the park position. Once
it's aligned, refasten the wiper arm in the correct parked position (try
NOT to turn the motor while tightening the nut holding the arm).
==============================
Section 19.5: Rewiring Fog Lights so they're independant of high beams
Instructions for E28 535i (should apply to any E28)
There are two philip screws which attach the top of the fuse box (or power
distribution panel as the book calls it) to the bottom of the box. Remove
these two screws. You may have to remove the relays above the screws to get
at them. Find and remove the fog relay (marked in the owner's manual and
the Bentley). Remove the connector in the top part of the fuse panel (it's
in the slots that you push the relay in) for the 85 lead on the relay (if
you look at the bottom of the relay, the leads are labeled with the numbers
30, 86, 87, 85...so on). The easiest way to remove the connector is to use
a very thin flat screwdriver and push on the back of the spade to push the
little tab back into the spade so it slides out the bottom of the fuse
panel. Drawing below:
| <-- thin screwdriver
|
______ |__________ top of fuse panel
|
|\ <-- push this tab in from above
| to slide connector out the bottom
Now pull the connector out the bottom of the panel by separating the top
and bottom halves of the fuse panel. The halves do not separate much maybe
3 inches. Tape this connector up or use shrink tubing. You won't be using
this connector again. The next step is to remove the connector of the 85
lead of the high beam relay (this is ground, you might want to test for
such) in the same way but you will use this again.
Make a y connector with two leads to fit in the two slots you just removed
the connectors from and the third lead to fit in the connector that was
connected to the 85 on the high beam relay. Plug the y connector in (slots
and the extra lead). Tape or shrink wrap the y connector to previous 85
high beam conector. All that is left is to plug in the relays and test the
new feature (fogs on even with high beams on) and put the two halves of the
fuse panels back together. TEST!! before putting the halves together.
Instructions for E30 318i (should apply to any E30)
Same as above except disconnect 85 on the fog relay and put the y-connector
to the connector on the 86 of the high beam relay (this is +12v when the
ignition in the run position) and the 85 lead of the fog relay.
- - ---
The nice part of this rewiring is that it is entirely reverseable since no
cutting is involved. I have seen as a Porsche mechanic too many car wiring
systems destoryed by poor rewiring for extras and especially sound systems.
I have also wired my fogs to function as longs as the light switch is in
the park or on position but that extra bit is more complicated than I can
explain in this media.
==============================
Section 19.6: Resetting service indicator lights
A: (by Jim Shank:shank@domain.elided)
Most people I know think the BMW service indicator light cicuit is totally
useless. However noone wants the damn lights on all the time and some
people (like me) like to keep everything working. So here's a file I've
been compiling on the subject. I've not check this on early model (pre '88)
cars but it's accurate for the later models. I've also not given credit for
some of the material because I forgot where I got it. Anyway here it is:
BMW Service indicator lights FAQ.
- - --------------------------------
The service indicator lights are reset through a pin in the diagnostic
connector located in the engine compartment.
There are 2 types of diagnostic connectors used on BMWs. One is a 15 pin
connector used on 1987 and earlier cars, the other is a 20 pin connector
used on 1987-on cars. In what follows the 15 pin connector is referred
to as the early type and the 20 pin as the late type. Resetting the
service indicator lights is described below. The most common problem
with resetting the service lights is bad NiCad batteries in the
instrument cluster. The batteries seem to fail pretty consistently after
4 years.
The symptoms of this are:
1. The inspection light comes on.
2. Resetting the light according to the instructions below either
doesn't work or works for a short period of time and then the inspection
light comes back on.
The fix for this is to replace the batteries as described below.
Relevant Roundel references:
- - ---------------------------
The Roundel is the monthly publication of the BMW Car Club of America.
Jan 1992, Nov 1991, Dec 1989, May 1988 -- Resetting the service
indicator lights
Nov 1991 -- Replacing the Nicads.
Resetting the service indicator lights.
- - --------------------------------------
Late type connector:
The service indicator lights are reset by connecting pin 7 to pin
19(ground). The proper way to do this is to have the ignition off and
place a jumper wire between pins 7 and 19 (make sure you get the right
pins!). Then turn the ignition switch to position 1 (accessory), when
the service light goes out, turn the ignition off. The difference between
resetting the oil service light and the inspection light is in the
length of time you have the jumper in place with the ignition on. This
means that if you are resetting the oil service light, you should turn
off the ignition immediately after the light goes out. If you leave the
jumper in too long with the ignition on, you will perform an inspection
reset as well and the next service indicator will come up as an oil
service rather than an inspection.
The service light reset tools that I have seen connect to 3 pins of
the diagnostic connector: pin 7,14 and 19. The connection to 14 is to
power the tool. The less sophisticated tool has only one switch that
connects pin 7 to 19. While those pins are tied together a red LED blinks
to measure time. You count blinks and manually turn off the tool after
the appropriate number of counts for oil or inspection reset. The more
sophisticated tool has two switches, one for oil reset, one for
inspection. It must have a built in timer that jumps pin 7 to 19 for the
correct time.
Early type connector:
The procedure is the same as above, but you jumper pin 7 (the service
indicator pin) to pin 1 (the ground pin).
The early type connector:
*******
**** ****
*** (10) ***
** (9) (11) ***
* *
* (2) *
* (8) (3) *
* *
* (7) *
* (1) *
* (4) *
* *
* (6) *
* (15) (5) *
* *
** (14) (12) ***
*** (13) ***
**** ****
*******
Diagnosis plug connections:
No. Terminal Designation
1 31 Ground
2 - -
3 - -
4 FT Temperature gauge
5 L Engin M10B18 Interfrator output for CO adjustment
Engin M30B34 Oxygen Sensor signal
6 A Diagnosis lead for SRS
7 SI Service indicator
8 P+ Position sender
9 S Shielding
10 P- Position sender
11 50 Starting pulse for starter
12 61 Alternator charge indicator
13 1 Ignition signal
14 30 battery +
15 15 Power supply for ignition
The late type connector:
** ***
**** ***** ****
*** (1) ***
** (12) (2) ***
* *
* (11) (20) (13) (3) *
* *
* (10) (19) (14) (4) *
* *
* (15) *
* (9) (18) (5) *
* (16) *
* (17) *
** (8) (6) **
** ***
*** (7) ***
**** ****
*******
Pin Wire Size Wire Color Circuit and Component Connected
----- ----------- ------------ ---------------------------------
1 1 BK Ignition Coil, Motronic Control Unit
6 0.5 WT/BK SRS Connector (Not Used)
7 0.5 WT/GN Service Interval Indicator, Service
Interval Processor(Reset).
11 2.5 BK/YL Starter, Start Signal(50)
12 0.75 BU Charge, Alternator(D+)
14 2.5 RD Battery
15 0.5 WT/YL Motronic Control Unit(RXD)
16 1.5 GN/WT Oxygen Sensor
18 0.5 GN/BU Motronic Control Unit(Programming Voltage)
19 1.5BR BR Ground Distribution(G103)
20 0.5 WT/VI Motronic Control Unit(TXD)
The Dummy plug.
- - ---------------
Late models:
The cap on the diagnostic connector is actually an electrical connector
that shorts together the following pins:
- - --pins 18 and 20 to pin 19.
- - --pin 14 to 15.