Hello All,

I'm new to the forum, but a long time visitor and Bonneville owner. Looking for some direction for ALL of the the following symptoms on my 2005 SLE (may be all by themselves or in conjunction with one another at any given time - symptoms began about three weeks ago :

Service Air Bag light comes on for a period of time ranging from 3 seconds to several minutes, then dash dings 3x light goes out
Check Charge System Light comes on, volt meter then goes way up or way down - sometimes will ding 3x and return to normal sometimes not
DIC goes out - may or may not come back on during that trip. Gages stick wherever they were when this occurs \ front windows and fan have no power when this occurs

This problem is intermittent; it may go several days/trip without any issues and then one or more of the above will occur within a five minute drive. The fact that the dash will ding 3x leads me to believe the instrument cluster is losing its ground connection, then regaining it - maybe I'm guessing wrong.

Any direction those more experienced could provide would be greatly appreciated.

Welcome!

This sounds very much like a low voltage problem. Start by checking all your battery connections. Sometimes corrosion builds up under the rubber boots of the battery cables. Check these, cleaning as required and make sure they are tight. Also, check the battery cable at each of the fuse blocks (under the hood and under the rear seat). You will also want to ensure the connections are tight at the starter.

How old is your battery? If none of the checks above resolve the problem, you may want to have your battery load tested and alternator checked as well. You have too many systems involved to make me jump to cluster wiring as a suspect. This would be an exceptionally uncommon problem in this vintage Bonneville simply because of how dramatically GM improved grounding.

Check these and let us know what you find.

_________________


Bose Luxury Sound System w/Touch Screen Navigation, Addition of Factory XM, 2005 MY Antenna, OnStar Upgrade (3G),
RainSense Wipers, Backup Camera, '00 Style Door Panel Courtesy Lights, Heated Washer Solvent, 2X Remote Trunk Release,
Turn Signal Mirrors, Center Console Courtesy Lamp, Rear Outboard Heated Seats, PVD Chrome 18" Factory Rims, Upgraded
Carbon Fibre Appearance Interior Trim, Highly Modified Main Body Harness, Instrument Panel, Door, Door Panel & Headliner
Wiring Harnesses, Custom Fuse Box & Tire and Loading Information Decals, Additional Acoustic Insulation

Thanks ddalder for the direction. Here's what I've found so far:

Negative battery cable - clean / tight
Positive battery cable - clean / cable didn't feel loose when gave it a tug, but I was able to tighten the terminal bolt 1/4 turn
Fuse block in back seat - clean / tight
Fuse block under hood - slightly dirty but tight, cleaned both sides of all connection surfaces and lightly coated with dielectric grease
Volt meter on battery with key off 12.7 volts
Volt meter on battery while starting 11.8 volts (I believe this is an acceptable drop while cranking)
Volet meter on battery while running 14.6 volts

I've driven more than a dozen drive cycles of various distances/times - There have been no recurrences of the Instrument Cluster warning messages. Because the problem was intermittent, I'm not quite ready to declare it solved, but it does appear that tightening the positive terminal and/or cleaning the fuse block connectors has made a difference thus far. I will give it some time and provide updates.