Airbag, Seatbelt AND Battery lamps! Arrrgghhh!

[Robert Coats]

So I’m just driving along in my ’91 C4 with 57k miles and the airbag, seatbelt and master caution (!) lamps all pop on. I use the cancel switch to make the master caution lamp go out, but the airbag and seatbelt lamps stay on.

Next, I do and note the following:

Unfasten my seatbelt, and then fasten it back (no change)

Arrive at my destination, and turn the car off. As I do, I catch a glimpse of the BATTERY warning light as it briefly flashes when I shut the car off. Hmmmmm. I never noticed that before. Maybe it’s a clue as to why my airbag and seatbelt lamps won’t go out? Let’s try again.

Sure enough, I restart the car, the airbag and seatbelt lights are steady, and, as soon I as I shut off the car, I see the BATTERY lamp flash, just for half-second or so.

Question #1: Does your BATTERY lamp flash briefly when you turn the car off?

Question #2 What would cause the airbag AND seatbelt lights to stay lit?

Question #3 Any troubleshooting ideas or places/things to check to solve this puzzle?

Question/theory….I have a hunch the battery may be dying. The car starts just fine, but the brief flash of the battery lamp at shut off doesn’t seem right. Maybe the seatbelt/airbag circuit senses the battery isn’t 100%, and that’s why they are staying on? Maybe the brief flash of the battery light indicates the battery is starting to die?

[Britwrench]

First of all check the battery connections and the ground wire.
Check the condition of the drive belts. Check the charge rate with a voltmeter.
With the engine idling, pull off one of the amplifier multi-plugs on the coils os that the engine will run on only one set of spark plugs...if it stops the belt may be broken, if it runs rough there is a ignition wire problem.

Either of the above will cause warning light displays.

I would also replace the fuel pump, abs and abs pump relays on this car as due to age and general deteriation those parts can (will) give problems.

[joabydal]

Did you manage to fix your problem?
I've got a similar problem with my 95 993 at the moment.
As soon as i turn the ignition off, the battery lamp comes on, and airbag + seatbelt lights come on very weak...

So hopig you got some good advise for me.

Thanks

Joachim