BMW 745i airbag light. Told to replacing airbag clockspring

There is a unit in the steering wheel, under the driver's airbag, called a clockspring. It carries electrical 'wiring' for the horn, the airbag, and any controls you may have on your steering wheel (cruise control, radio controls, etc). You probably have some wear such that when you turn the wheel (causing the clockspring to compress or relax) the 'wiring' completes the circuit for the horn relay. You will need to replace the clockspring. If you do this yourself, BE SURE you disconnect the battery and allow 30 minutes or so for the capacitors for the airbags to discharge.

read the manual, yet, ?
the service manual. be like first ....
do you want dead air bags, in an accident.???
the clockspring runs many things.

step one is shut down air bags. or risk personal injury.
chapter 8L covers this and 8O, and is not trivial at all.
easy to take anything apart , harder back'
I have no idea at all what you dismantled, not a clue.
and is key to the answer, for sure.

installing CS is chapter 8O (oh as in Oscar) service manual.
INSTALL.
WARNING: To avoid personal injury or *****, on
vehicles equipped with airbags, disable the supplemental
restraint system before attempting any
steering wheel, steering column, airbag, occupant
classification system, seat belt tensioner, impact
sensor, or instrument panel component diagnosis
or service. Disconnect and isolate the battery negative
(ground) cable, then wait two minutes for the
system capacitor to discharge before performing
further diagnosis or service. This is the only sure
way to disable the supplemental restraint system.
Failure to take the proper precautions could result
in accidental airbag deployment.
CAUTION: If the clockspring is not properly centered
in relation to the steering wheel, steering
shaft and steering gear, it may be damaged. (Refer
to 8 - ELECTRICAL/RESTRAINTS/CLOCKSPRING -
STANDARD PROCEDURE - CLOCKSPRING CENTERING).
Service replacement clocksprings are
shipped pre-centered, with the release button
engaged (raised) and a molded plastic shield
installed over the release button. This release button
should not be disengaged and the shield
should not be removed until the clockspring has
been installed on the steering column. If the release
button is disengaged before the clockspring is
installed on a steering column, the clockspring centering
procedure must be performed.
NOTE: Before starting this procedure, be certain
that the front wheels are in the straight-ahead position.
(1) Carefully slide the centered clockspring down
over the steering column upper shaft until the two
integral plastic latches on the back of the clockspring
housing are fully engaged through their openings in
the steering column lock housing (Fig. 17).
(2) Reconnect the two instrument panel wire harness
connectors to the two connector receptacles
located below the steering column on the back of the
clockspring housing.
(3) Position the upper and lower shrouds onto the
steering column.
(4) Align the snap features on the lower shroud
with the receptacles in the upper shroud and apply
hand pressure to snap them together.
(5) From below the steering column, install and
tighten the two screws that secure the lower shroud
to the upper shroud. Tighten the screws to 2 N·m (18
in. lbs.).
(6) If the vehicle is equipped with the optional tilt
steering column, move the column back to the fully
raised position and move the tilt release lever back to
the locked (up) position.
(7) If a new clockspring has been installed, remove
the plastic shield covering the release button that
secures the clockspring rotor to the clockspring case
to maintain clockspring centering.
(8) Reinstall the steering wheel onto the steering
column. (Refer to 19 - STEERING/COLUMN/STEERING
WHEEL - INSTALLATION).
NOTE: Be certain that the steering wheel mounting
screw is tightened to the proper torque specification
to ensure proper clockspring operation.
(9) Reconnect the steering wheel wire harness connector
to the upper clockspring connector receptacle.
(10) Reinstall the driver airbag onto the steering
wheel. (Refer to 8 - ELECTRICAL/RESTRAINTS/
DRIVER AIRBAG - INSTALLATION).
(11) Reconnect the battery negative cable

Hi, odds are your clockspring has broken. You'll have to remove the steering wheel to access the clockspring, which will require the use of a steering wheel puller. I have pasted procedures below from autozone.com. After removing the airbag and before removing the steering wheel, you can verify that the clockspring has failed, if desired, by testing the continuity of the wires from the airbag to the bottom of the steering column. Please let me know if you have any questions, and thanks for using FixYa.
Removal & Installation CAUTION The Supplemental Inflatable Restraint (SIR) system must be disarmed before removing the steering wheel. Failure to do so may cause accidental deployment of the air bag, resulting in unnecessary SIR system repairs and/or personal injury.

1. Make sure the front wheels are in the straight-ahead position.
2. Turn the ignition key cylinder to the LOCK position and remove the key. Turn the steering wheel a half turn toward the left until the steering column becomes locked in position.
3. Remove the 3 bolts attaching the air bag module to the steering wheel. Remove the air bag module.

CAUTION Disconnect and isolate the negative (ground) battery cable. Allow the system capacitor to discharge for at least 2 minutes before continuing with the removal procedure. This will disable the air bag system.

Fig. The airbag is attached to the steering wheel by three fasteners


Fig. After the airbag is unbolted from the steering wheel . . .


Fig. . . . reach behind and unplug the electrical connections

4. Disconnect the wiring connectors from the air bag module, horn switch and speed control switches.
5. Remove the routing clip for the wiring harness from the air bag module studs.
6. Remove the steering wheel mounting nut from the steering column shaft and remove the steering wheel damper from the steering wheel.

Fig. Always hold the airbag away from your body when transporting it to a storage area


Fig. With the airbag removed, the steering wheel retaining nut can be removed


Fig. After the nut is removed, set aside the damper plate . . .


Fig. . . . and use a paint marker to matchmark the steering wheel shaft with the wheel

7. Using a steering wheel puller tool, remove the steering wheel from the steering column shaft. Do not thread the steering wheel puller tool bolts into the steering wheel more than a 1/2 in. or damage to the SRS clockspring will result. Do not hammer or bump the steering column or shaft when removing the steering wheel
8. Remove and replace the clockspring.


Fig. A steering wheel puller must be used to remove the wheel from the shaft


Fig. Once the wheel is free of the shaft, carefully route the wires through the wheel

To install:
1. Before installing the steering wheel, the clockspring must be centered . Center the clockspring as follows:
a. Disengage the lock mechanism by depressing the 2 plastic locking pins.
b. Turn the clockspring rotor clockwise until it stops, while the lock mechanism is disengaged. Do not use excessive force.
c. From the end of the clockwise travel, turn the clockspring rotor counter-clockwise. The clockspring wires should be at the top. Engage the clockspring locking pins.
d. Turn the clockspring a 1/2 additional rotation counter-clockwise from the center locked position. This should put the clockspring wiring at the bottom.
e. The clockspring is now correctly positioned for installation of the steering wheel.

2. Install the steering wheel onto the steering column shaft. Make sure the master splines of the steering wheel and steering shaft are in correct alignment. Be sure the flats on the steering wheel align with the formations on the clockspring. All wiring leads from the clockspring must be routed correctly.
3. Install the steering wheel damper onto the steering wheel in its original position.
4.Install the steering wheel-to-steering shaft retaining nut. Torque the retaining nut to 45 ft. lbs. (61 Nm).
5. Reconnect the horn switch wiring lead from the clockspring, onto the steering wheel horn switch wiring.
6. If equipped with speed control, reconnect the speed control wiring from the clockspring onto the speed control switch.
7. Install the wiring lead from the clockspring onto the air bag module. Make the wiring connection onto the air bag module, by pressing straight in on the connector. Be sure it is fully seated.
8. Install the air bag module to the steering wheel and then install the 3 air bag module attaching nuts. Torque all 3 air bag module attaching nuts to 100 inch lbs. (11 Nm).
9. When reconnecting the battery on a vehicle that has had the air bag removed, the following procedure should be used:
a. Connect the DRB or equivalent scan tool, to the ASDM diagnostic 6-way connector.
b. Turn the ignition key to the ON position. Exit the vehicle with the DRB, and install the latest version of the proper diagnostic cartridge into the DRB.
c. Make sure there are no occupants in the vehicle and reconnect the negative battery cable.
d. Using the DRB, read and record active or stored fault codes. Take appropriate actions to correct any faults.
e. Erase stored fault codes. If problems remain, fault codes will not erase.
f. From the passenger side of the vehicle, turn the ignition key to OFF and then ON , observing the instrument cluster air bag lamp. It should go ON for 6-8 seconds, then go out. This will indicate that the air bag system is functioning normally.

WARNING If the air bag warning lamp fails to light, blinks ON and OFF or goes ON and stays ON, there is an air bag system malfunction.

g. Test the operation of any steering column functions such as the horn, lights or speed control system.
h. Road test vehicle. Be sure the speed control and steering systems are functioning properly

Since I can't find a bad fuse, I'll check the clockspring.
You must emove the air bag in the steering wheel to get to the clock spring. Unless you feel you understand the air bag system 100%, and feel comfortable disconnecting the air bag, I suggest you take it to a professional for repair. This is not hard to fix. The Airbags are already disabled by if your airbag light is on. This is done automatically when the system senses a fault to protect occupants. What you have to do is unsrew the 2 screws on the side of the steering wheel and then remove the cables that go to the airbag and cruise control. Then you need to unscrew the one star bolt that holds the steering wheel in and use a steering wheel pully to pull off the steering wheel and there should be 3 screws holding the clockspring in. You need to remove the clockspring and replace it with one from the junk yard. Theres no reason why someone should charge you for more than 1 hour labor to do this. It doesnt take longer than that make sure you dissconnect battery first before you do this is your air bag light staying on

try to look for a fuse.

This is due to a broken clockspring behind the steering wheel. It works as a constant contact for all acessories on the steering wheel to include the air bag system. It is a simple ribbon of wire to allow for turning of the wheel incased in a plastic housing that shouldn't be messed with. If you mess with it internally, you run the risk of the airbag deploying in your face!! It is best purchased from BMW.

sounds like a bad clockspring. located in steering column under steering wheel, operates airbag, horn cruise etc, it make wire connection possible so the wheel can spin, its a roll of flat wires, that unroll and roll up as steering wheel is truned from left to right,wires break after a while.

As long as the light is on the airbag system is disabled.

I would suspect that your clockspring behind the steering wheel is going bad. I would have someone with a scan tool that is able to retrieve trouble codes from the airbag system check it for codes to verify this. If so then steering wheel and steering column trim would have to be removed to access the clockspring to replace it.

The Airbag, horn and cruise control share on common component. The clock spring inside the steering wheel. The clockspring is snapped into a plastic mounting platform on the steering column behind the steering wheel. The clockspring is used to maintain a continuous electrical circuit between the wiring harness and the driver's airbag module. This assembly consists of a flat ribbon like electrically conductive tape which winds and unwinds with the steering wheel rotation.
The clocksprings going bad is a common problem with Chrysler products. Since the Airbag is involved, I would recommend the dealer replace it. It is about a $175.00 to $200.00 repair. or you can try junk yards hope this help have a nice day.