Hello,

I am looking to replace the positive battery cable in my R53. I am wondering if there is anyone here who has done the job and can give me some insight and lessons learned.

I understand from the Bentley manual that the cable passes from the interior to the exterior in the front of the battery compartment. It then passes above an exhaust heat shield, veers to the left side of the car, and runs up to the engine compartment. It doesn't seem to get more detailed than that. How many parts need to be removed to do this replacement? Is it all straight forward removal of heat shielding, or is it more complicated than that? I searched for a thread on this, but did not turn up much. One thread suggested the whole interior of the car had to be taken apart, but I think that can't be right.

Thanks.

 

The biggest headache is you have to remove the exhaust in order to remove the heat shield. If you're feeling really lazy you might be able to bend the shield and snake the cable through.
After that it's pretty straight forward as the cable runs adjacent the left rocker panel and is readily accessible underneath the car.
IIRC, there might be a few items to remove at the front of the car but nothing too crazy.

 

Thanks for the response. Well of course I am feeling lazy! I live in the Northeastern US, where the exhaust is likely to be a rusty mess. Hmm. I need to get this thing on a lift and have a look-see.

 

I'm just curious why you need to replace the entire cable.

 

^^^
I have an airbag light on, with a code pointing to the battery safety terminal/battery cable.

 

My '02 doesn't have that terminal, but I'm pretty certain you can just replace the fuse in it, or the terminal itself, not the entire cable.
Others will know better!

 

The 'squib' in mine is long gone, and I have seen no documentation of what that part was. So I have no idea what to replace it with. I believe the squib is the yellow electronic device that resides on the end of the battery cable and triggers the charge detonation to separate the cable when so instructed by the airbag controller.

What build month is your '02?

 

May 14th 2002 - US spec

Try this:
https://www.northamericanmotoring.co...Ng2GmT2GSai04g

or this:
https://www.facebook.com/groups/1545...earch/?q=squib

 

Thank you for the links. I can't see the facebook one (I'm not on facebook), but the solution at the NAM link doesn't actually restore the safety functionality. It just uses a ~3.2 ohm resistor (of appropriate power rating) to fake out the airbag controller. The resistance is chosen to make it look to the controller as if the integrity of the cable is good. But in the event of an accident, the cable would not behave as designed.

I want to restore the original safety functionality. And that is why I am replacing the whole cable, expensive and difficult as it may be.

I wonder if anyone has reverse engineered the BST, so that it might be repaired.

I should note, I know there are several threads here and elsewhere documenting the fake out resistor, and I am sure that this is the most popular path. What I have not found is documentation of NAM users replacing or repairing the cable itself.

 

Check this thread: https://www.northamericanmotoring.co...ml#post4592801

in my case I cleaned the connector / plug and error / airbag light went away

 

I had not seen the video in that thread. Still, I haven't been able to turn up the repair kit, and I don't have the yellow part (in the video he says, be careful with the yellow part, because if that's damaged, it's not good).

What is interesting is that in the video he also claims that the job is an interior job. That's not what the Bentley manual says, and not what mrbean said, above. Strange.

I wonder, given that this is a safety equipment issue driven by water leaks, why NHTSA never got involved with it.

 

I can get a pic of mine if it helps?

 

Thank you, but that won't be necessary. There are photos of the assembly end on ebay. I have already resolved that I will install an entirely new cable. I'm just looking for hints from those who have done the job before.

 

Sorry to revive an old thread, but I'm about to do this job and I was wondering if the OP learned anything in the process.

WhoHasGotTheBlueS, how'd the positive battery replacement project go?

 

Haven’t ever found the time to do it. Hopefully this summer, but there are more pressing issues with the car to address at the moment.

Did you do the job?