PontiacBonnevilleClub.com

Spoiler alert! - SInce this is "solved" may as well let you know what happened. After conflicting opinions between some mechanically experienced friends and the Pontiac Bonneville Club board online the Pontiac Bonneville Club board was correct that it was a problem with the Ground Bus. In this case the Passenger side one. Photos and details below. It was pretty easy to remedy, under 1/2 hour really once you know where it is and what you're doing (which if you don't look below and you might). I should mention though the car had the alternator replaced when restarts became impossible. Don't know if that was a costly un-necessary repair but at least the alternator should be great for a long time now too.

Hmmm… and then the power door locks stopped working... At first that was the only symptom and there was no related noise. I figured it was the fuse and upon checking the manual saw it was one contained in the passenger floor-well panel so "have to get to that when time allows". Next I noticed that when I pushed the button a noise started happening and I think it's the relay. (Sounds like a [url=http://en.wikipedia.org/wiki/Güiro]Guiro[/url]). and others suggested "It's the relay" same spot? Any suggestions on how easy to replace this is?
BUT then yesterday when driving home (45 minute commute) I saw the "Volt" light illuminate and soon, the AC shut off.I'm hoping this may be related as I just forked over about $500 to have the compressor replaced. The ABS brakes and Traction control also illuminated (and I'm thinking the control module is shutting off peripheral things to preserve electricity for the engine?) Mostly I'm thinking "come on! what now?" after also paying too much to replace worn rear shocks and hoping I could catch a break for a month or two. I love Bonnie but really need a repair break for a bit. (admittedly I had one for a while) Any insights greatly appreciated.

Sounds like there's just a lot of electrical things popping up at once. I'd check the ground busses under the drivers and passenger side foot wells. They can corrode and cause some weird electrical things. Try cleaning those up and see if that makes any difference.

Also check the battery connections, and have the battery tested. My 96 did that and I replaced the battery and all was well.

Will check Battery Cables Then Battery and Busses. I found a link to images of accessing ground bus here. Thanks both.

http://www.pontiacbonnevilleclub.com/fo ... ml#p301518

I got myself ready to dive into this!! but then had to pause. I was beginning to tear up the trim around the lower door and remembered "I don't really know what I'm doing, I should ask others about this BEFORE I go breaking stuff". So I'm back. I looked but didn't locate a detailed (novice) level breakdown of removing the trim to access the bus.

Looks like the drivers seat should be removed and then what?
Is this possible without removing the drivers seat?
Rear edge (back-seat) of trim first?
Um, What were they thinking? What problem did this design solve?
I'll try to do an illustrated how-to if it doesn't yet exist. (if you know of a link to that, send it…)

Also, while in there I spotted water in the floor-dip where (what I think is) the brake line goes below the cabin. Would we guess more likely from the doors or sunroof drains? (Please let me know if I should make a separate post for that).

Thank you! Pontiac Bonneville Club.com forever! (cool, it auto changed p-b-c to the full name - nifty!)

They are further forward than the seats. The trim should just pop up with a butter knife. Be careful of the hood release when you do the driver side one. The ground bus will be just under the carpet there.

Thank you Haro, will be going back into the trenches this weekend and will reply back when hopefully things are back to normal.

OK, maybe getting closer, I pulled up the carpet on drivers side floor, I see this with wires going in.
I'm guessing the magic bus is in there?
Not sure how I get into that. Didn't want to start yanking on it and make it worse.



After driving Cammie (Not Bonnie) for the past weak, Bonnie is pretty weak.
Definitely an electrical thing happening. Dashboard lights completely dimmed.
Can't power the OEM hand spot light very well even running.
Poor thing was ready to shut down by herself so I stopped the engine.
Battery cable was recently attached and looks clean and still connected.
Just did that about a month ago.

...and here is the floor pan wet area I mentioned above.
Anyone know where that might be from?
(besides "outside" or "the sky" - but thank you anyway )

The ground bus is the square thing wrapped in the tape. After you unwrap it, there is a blade in there, take it out and clean it up, and see if it changes anything.

And now I can't open the gas tank door because it's perma-locked?… (is there a way to force unlock the fuel door cover when the car won't trigger it because the locks are locked out)

Been a couple of weeks since I've had even a moment to login and update the status. Sadly I'm not through the woods yet. Before I could get back and review the ground busses the whole vehicle enectro started failing. Had to hook up the tow trucks charger battery to get up the ramp. Took it to Pep Boys (don't have a local garage or mechanic … yet) where for about $310 they replaced the alternator and that got the system startig and charging. My Driver Info Center illumination might be a little more stable then before ( ? ) But locks still not working and as a result I don't know how to fill up the tank.

Then possible connections to the water issue. I called my local (near office) mechanic who'd installed a compressor a few weeks ago because I needed air pressure to blow out the sunroof drainage tubes. He told me it was more likely the condensation drain from the AC. So I brought Bonnie the Garage and left her with the man. I had purchased a relay which the mechanic and another friend said was likely causing the noise and lock failure.

I think the AC drain is fixed and no more water happening though it's been cool outside. Anyway, now my Mechanic told me it isn't the relay it's the Body Control Module (oy!) SO I returned the relay, ordered a BCM from Rock (and darn if I didn't forget to apply our Pontiac Bonneville Club discount coupon!) and it's on its way. Then another mechanical fellow I know shows me he found something indicating that the BCM had to be Flashed to connect to the VIN of the car it's being installed in.

Apparently this little number is behind the glove box insert and I'm told pretty accessible. I hope so. Not sure which issue I'll tackle first the BCM or Ground Busses but both are on the list. Oh, one reason I'm leaning toward BCM is that I can't open the fuel door now. It has an electronically triggered lock and I haven't seen a place to over ride it.

So the two questions I arrived at are:
1. Do I need to have a dealer or anyone flash a new BCM going into the car?
2. How to over ride the locked fuel door.

There's a lever inside the trunk near the gas door area.

Haro! You rock, thank you. Do you know about the BCM issue and whether anything needs to be done to prep it or can I just replace the original and good to go?

There she is, thanks for the prompt, would have ended up checking there , and probably noted in the manual too. Latch was astern of the driver side rear wheelwell and the white lever slides into and from the unit unlocking the door. Easy peasy, I hope the BCM is easy. Will try to force time this weekend to look at the ground busses too.

Did you take apart the ground bus, check for corrosion, and use dielectric grease, then check to see if function has returned? ?

I've been a member here for quite a while, and can't ever remember a BCM going bad. I think you need to do the basics, like cleaning the battery cables, get the battery stress-tested, and cleaning the ground busses before throwing parts at the car.

Hi Bob, I'm guilty as charged.
My schedule has been insane so just taking some of the nearest advice I can get (and trying to pay others to make it go away!) but haven't had any weekend time to address the ground busses. I did try to get to it once (as seen above) but had questions and decided it might be unwise to just go haphazard. Since then, it's been one distraction to the next bookended by 40-hour grinding workweeks and 10 hours commuting. My work contract ends this week so looks like I'll finally have a little time to treat Bonnie right.

I think water was/is finding it's way into that area so corrosion is likely. Battery seems clean I just re-cabled that a month or so back. Thanks for the encouragement, before I even open the BCM (which arrived today) I'll make sure those are clean. Nobody has answered the "will it need to be flashed?" question yet. It would be interesting to know. thanks.

jonnevilleSSEi wrote:Nobody has answered the "will it need to be flashed?" question yet. It would be interesting to know. thanks.

Me too. I have no idea. It seems unlikely.

The ground buses are simply a blade and socket arrangement, like a light plug. Just unwind the tape, separate them, and if there's corrosion there, wire brush it off and use dielectric grease, reconnect, and you're done.

Good luck.

Ding Ding Ding we have a winner @ Pontiac Bonneville Club! So the Body Control Module is being returned. I opened up the carpet and Ground Bus Connections and it ranks in the "I should have made the connection earlier". Since I knew about the water leak etc.
Here's a clear image of what the Ground Bus connection looks like untaped and out of the conduit. So if anyone else wanted to know, this is what I faced. It's pretty tight in there and sits behind a metal brace. It was a little tight but I slipped it out from under that.


That was the driver side and nothing happened when I took that out, but the passenger side is a different story. Saddens me to see all this moisture down here and the oxidation too. I could see the interior lights start to flicker as soon as I moved the unit. I'll be back soon to add small descriptions to the images, meanwhile, this is what the job looked like.

I was under the impression I'd be removing the wires, cleaning stuff out and replacing them. So far I just fixed it by jiggling it and snugging the fit. What do we recommend for getting the wires out? Should I use a needle nose and pull them out? Push them out from the reverse? Right now it's all loosely dis-assembled to encourage the carpet to dry out. Before I put it back together I'd guess we want to take the wires out, clean all connections, apply electrical lube and then tape it back up.



I also need to monitor the water and see if it really is now just a drainage remnant from the AC or if this is something else. I had the man use an air hose to blow out the front drainage tubes around the sunroof.
I looked for and didn't see any behavior changes from the DIC. Any chance the blinking DIC and dashboard issues could relate to ground bus corrosion? I was really hoping they were connected and corrected too.
Thanks for the help with this and reminder to check the ground bus.

jonnevilleSSEi wrote:Here's a clear image of what the Ground Bus connection looks like untaped and out of the conduit. I'm going to add more helpful (I hope) images shortly but the wife is calling with her list now (augh).
Thanks for the help with this and reminder to check the ground bus.

We all love a happy ending.

Now, please edit the topic of your post to add "solved" at the end of the title to simplify searching for those who search this problem in the future.

Did that, great suggestion. On a second review it looks like the Blade slides out from the Bus to clean it or access the connection. Going to look at that, may add other photos.
… and so here …

After using a pliers to grab and wrestle the ground blade out. On my way now for dielectric grease.

jonnevilleSSEi wrote:Did that, great suggestion. On a second review it looks like the Blade slides out from the Bus to clean it or access the connection.

Yes, it does. Wire brush the contacts and use dielectric grease on both the blades and sockets. Slide them in and out a few times to ensure a solid ground. Should cure your ills.