I am helping my dad troubleshoot a few issues with his 96 bonneville, but some of this has left me stumped. Unfortunately (forunately?.... ) I am a german car guy, so the way this car is built confuses me sometimes.

At present, he has a mal-functioning ECC. It looks like it is the air mix motor. He has almost no control over whether he has heat or not. The climate control does nothing on it'* own, but if you change the temperature, then bang on the dash a couple times (his solution, not mine), it will usually end up set correctly. I've done some searching on here, and that is what I believe to be the problem. For a short while his ECC display was flashing indicating a problem, but he did not know anybody who could read the code, and it is no longer flashing. Is it too late to retrieve the code? Are we somewhat correct in our assesment of the problem?
Does the passenger side airbag have to be removed to fix this, and if so, is there a procedure somewhere for the removal of it?

Next up is the one that has us stumped. After some banging on the dash, his interior convenience items are acting up. If this was a german car I would say it'* the convenience module, and that it is related to his heat problem, but I am not sure if this has one, and if so whether it is combined with the ECC?
For example, he will start his car, and have no seatbelt warning light/chime. However, upon shutting his car off, when he retracts his seat belt, the chime will go off, and the interior lights will come on. Before he has opened his door.
This only happens sometimes, and occasionally it will manifest itself in other ways, randomly chiming, the interior lights act almost as if posessed, and he is concerned that they will simply stay on one day, and drain his battery.
Is there a convenience module of some sort, and if so, is it by chance located under the passenger side of the dash somewhere?
Is it primarily constructed of relays and other devices that may have been damaged by the repeated banging on the dash?

Next up is the burned-out radio bulb. I know all about fixing it, but for removal of the radio, can we just pull the trim piece surrounding it straight off, or are we missing some screws or other pieces that must be removed first?

Thanks in advance for any advice you guys can give!

Zero...Hi and welcome..

All good questions I believe we can help you with.

The ECC has a learning procedure and also a fixing procedure that has been found within the last year. Please see the below thread for all the information.

ECC Thread

There is a convience module, it'* typically referred to as a BCM or Body Control Module and there is also another name that currently escapes me. It is located up under the passenger side hush panel (above feet and is the larger of two modules hooked to a white plastic supporting frame. There are tests that can be performed to test it'* functionallity. Hopefully someone has their online manual and can paste in some instructions for you, or I can get it in about 8 hours. I doubt you hurt it by banging on the dash. Maybe it was loose.

Radio light bulbs. There is a thread with the part number and company to order from below.

Radio Light Bulb

And just for peace of mind, check his driver'* side carpet for moisture/dampness and report if you find any.

I read a few ECC threads, but somehow missed that excellent tutorial. I'll try to get him to bring the car by this week and we'll take a shot at it.
Sounds like we'll end up replacing the air mix actuator, since it sounds unpleasant to have to go digging in there later.
The instructions are kind of vague. They say to disable the airbags, but they don't say to remove them?... I don't see why they need to be disabled.
If we trigger an airbag light, can we reset it without the scan tool?

As far as the radio goes, I think I'll put a LED in it'* place. I have done a lot of LED vehicle lighting, and this would be an easy project. He'* just worried about damaging the trim removing it. Does it just pull straight off?

Will he need the fancy little diagnostic tool to check the BCM as well?
I've never heard of one going bad, but it really sounds like his has. Hopefully it'* not an expensive part.

Now, the driver'* side carpet dampness?.... Just what should he start worrying about now?
If it'* sunroof related or something like that, his car doesn't have one.

Disabling the airbags is a precaution to ensure you don't actually set one off accidentally while you're under the dash. It could be dangerous.

The carpet dampness question may not apply here, but there has been a corrolation at times between wetness under the carpet and electrical anamolies. There is a ground buss down there (under the carpet by the driver'* side door) that can get corroded.

Moisture can come from other sources than a sunroof, if there is a problem.

and yes..the trim around the radio and lower dash simply pulls off..

Is the instrument cluster grounded at that ground bus?
His volt-meter has been reading rather low lately, but we are getting 13.95V at the battery. It sounded rather like a grounding problem to me, but I didn't know where the grounding points were. I'll check that out as well.

I believe it is.. would need to confirm in a manual that is at the other place at the moment. The key on the ground buss is pulling up the carpet right at the door and looking for corrosion or previous wetness problems.

A low reading gauge if it'* been consistent could be a gauge inaccuracy issue..

I figured I would add a couple of comments to help you along.

First, even though the ECC has stopped flashing, the code should still be stored, but as you may have read by now, requires a "Tech" scantool to retrieve the code.

The BCM (also known as the MALL) controls the chimes, interior, lights, and door locks primarily. Here is a thread that I have been invloved with that describes several diagnosis techniques and tests for the BCM/MALL. We have not yet solved the other persons problem, but are still working on it

http://www.bonnevilleclub.com/forum/...ic.php?t=53643

and like MIke has said, disabling the airbags is a precautionary measure so one doesn't deploy (electronically) while fiddling in the dash.

So, we took a crack at getting it all apart, but we are slightly confused, so I'm back here with pictures asking questions instead of taking things apart that we can't put back together.
It seems there are a couple brackets that are attached with bolts that have nuts on the other side, however the nuts are not welded on, and are just loose, with no easy way to access them. I think we are going the wrong way.

So, here'* a pic of it with the glove box out, if somebody could put some arrows in showing what we need to take out next, and where the air mix motor is it would really help.

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