Cruise Control and Horn doesn't work, Air Bag Light On
 

Hey!

I have a 2005 MCs that just blew a motor. I replaced the motor with a used one. Since the replacement, my airbag light is on all the time. Also, I noticed that the horn and cruise control don't work. When I press the power for the cruise control, I don't have the indicator lamp light up. First, I would like to mention that I was in audio install for a few years so I checked all fuses both inside and under the hood using a multimeter. One fuse was blown, it was the one that looked like a gauge cluster. After replacing that fuse, nothing seemed to change and that fuse didn't blow again.

I checked all harnesses underneath the two seats and under the steering column. Everything is plugged in and there are no loose/broken wires. Is there a relay that may be the cause of all 3 issues? Or could there be a harness I'm not aware of in the engine bay?

HELP!

Thanks!

My money is on the clock spring was damaged.

When changing engines did you guys remove the steering gear? If so there's a good chance the steering wheel got spun around and ruined the clock spring.

I will have a spare clockspring i'd part with if you make sure that's the problem.

Pull your airbag codes, I bet it says drivers inflator circuit resistance high, in otherwords, wire is broke.

How do I check for a bad clock spring? I'll have to see if I can get a scan tool to read the code for the airbag. Will the clock spring be the cause of both the horn and cruise? Are there any other signs of a bad clock spring?

Thanks!

I just talked to the guy that replaced my motor. He said he did remove the steering gear and that he thought it probably happened when he removed the rack and pinion. I just did some looking up and that would be the cause to all those issues.

If you knew a way I could test it, it would be very helpful. I wouldn't want to go through pulling off the steering wheel if I don't have to.

Thanks!

The only way I can think of to test it is print a schematic of the clock spring circuit, pull the air bag, disconnect the electrical connector under the dash for the clock spring, then using a VOM check for continuity between each end on each wire.

Test if you like, but if the guy didn't lock the steering wheel, I mean if it even rotated ONE turn then got put back together it upsets the "centering" of the wires and they break the first time you turn the wheel to full lock one direction or the other.

Horn, cruise not working, airbag light.....

IMO not much more testing required. Those are a dead giveaway.

AND do it soon..........
If the clockspring is broke it could cause your driver airbag to deploy AT ANY TIME!

it carries +12v for the horn as well as the airbag firing lines, get them shorted and BANG!!!!

Wrong.

To activate the horn the horn signal wire is grounded. They do NOT run +12v through the clock spring.

Glad you got it fixed!

So the horn switch grounds what then?

A positive voltage of course......

http://www.bmw-planet.com/diagrams/r...0000016976.htm

provided by Fuse 29..................via Horn Relay K2............

Beleive me I have seen this happen at the Oxford Factory, luckily no-one was hurt. Caused by the steering rack to column lower UJ being out of phase upon reassembly....

The few milliamps of current that gets grounded isn't enough to trigger an airbag.

I know this was a while ago, but I had the same problem, so I got a new clockspring, is there any way to verify that it is centered before I put it in? I don't want it to break again and have to start from square one...

It has been a long time but yes, it was the clock spring. If you turn the new clock spring until you feel resistance you will want to find center that way. Turn it until it stops. Then you will be able to make 5 rotations until it stops again. Center is 2 1/2 turns. Obviously make sure your tires and steering wheel are centered as well. Good luck!

YES it is, more than 5 milliamps will deploy the bag, the horn relay pulls way more than that!

Just bought a 2006 r53 S.

Horn doesn't work
Cigarette lighter doesn't work
Airbag light is on.


All fuses are good.

Does the cigarette lighter connect into this system also?

Anyone know the part number for the correct clock spring?

Don't have cruise control.

Finding a few different part numbers. Cannot find a definite on which i need.

Use your VIN number to find the right part with the dealer