2000 LeSabre - Strange Electrical Problems

I left my car parked while I was on vacation for a week, and the first time I tried to drive it after getting back, it started doing some weird things...

The engine starts and runs fine. But the dash lights will stay on--in different combinations, depending on what mood it happens to be in. "Traction Control," "Security," "Air Bag," and the "brights" indicator are all among the lights that may come on and stay on. The radio/CD player doesn't work. The A/C won't work. The fuel level and coolant temperature gauges are dead. The gear indicator doesn't light up. Can't use the power door locks or power windows.

There are things that still work OK: I don't have any problem with the headlights or turn signals. Engine rpm and vehicle speed gauges work. Odometer and trip counter data is OK.

I have found over the past few weeks that if the outside temperature gets above about 80 deg. F, things start working right again. Above 90 deg. F, you wouldn't know anything was wrong. With the weather here getting cooler now, it's on the fritz pretty much all the time, but sometimes while I'm driving along, the gauges and radio will come back on temporarily. Usually, they drop out again after a few seconds. Sometimes while driving, the door locks will tweak on their own when the system "comes back," or you might hear the "chime" you get when you put the keys in the ignition.

I have also noticed that when the system is in its "dropping in and out" mode, it will often "come back" after or during a braking event. I drive over some rough roads out here in the sticks, but I can't see that the behavior is linked to vibration.

One other possible clue is the fact that if the key is in the "On" position *without* the engine running, things seem to work right.

So I am wondering if I have a screwy BCM (body control module) or if it's just a bad power or ground connection that I will have to chase down. I am guessing a new BCM from the dealer would not be cheap. The local parts store says they'd have to order one, and didn't even have a price for it. And I have no idea whether getting one from a salvage yard would work out if it doesn't have exactly the right "software" for my car.

Has anyone else out there experienced something like this?

I left my car parked while I was on vacation for a week, and the first time I tried to drive it after getting back, it started doing some weird things...

Has anyone else out there experienced something like this?

First guess is that you have a bad ground connection or your battery is in bad shape and sitting let it move a step closer to replacement.

Check grounds at the floor of the rear seat next to battery; there's a star washer for good contact so be sure there's bare metal and tighten it well. Check the battery cables at the battery for corrosion.

But I'd check the battery. I'm guessing it's original... it could be almost 10 years old this month if the car were bought early.
In fact personally, I'd replace the battery unless it's reasonably new, because it's likely to go soon.

Good luck and let us know what you find.

Sounds like you might have had some critters doing some wire chewing. A bad ground is a possibility. It won't hurt to dig into the options that aren't working to gather a little more information.

Our 2000 was having intermittent problems like this before we traded it. It had the original battery and giving it an overnight charge seemed to eliminate the problem for a few days. Then it would come back. Another charge, and a few days fine. The alternator tested fine, so I assumed it was the battery on its way out. Never did determine if it was the battery for sure, as stated, we traded the car, in May. Check your battery and alternator first. It may be a cheap fix. Good luck.

Thanks for the responses thus far. I will take a look at the battery--I need to learn how to find it anyway...bought this not too long ago and never had a car with the battery under the seat before. I would impressed if the battery could be 10 years old. I've never had a battery last more than five years. Will check and get back w/results.

Thanks for the responses thus far. I will take a look at the battery--I need to learn how to find it anyway...bought this not too long ago and never had a car with the battery under the seat before. I would impressed if the battery could be 10 years old. I've never had a battery last more than five years. Will check and get back w/results.

The back seat just lifts up for access.

The location keeps the batteries from being hurt by excessive heat of the engine compartment so the life is longer.

I finally got around to attacking this problem today. Probably will never find a cheaper fix. I took the back seat out and saw where the previous owner had installed the power hook-up for a third-party security system. It stuck out like a sore thumb...the fancy wire with the clear red insulation that car audio places would use, tied off to the (+) post of the relay center. It had about 18" of electrical tape wrapped around that end, with a nasty-looking splice and fuse wadded up in it. The other end went under the carpet, up front somewhere. I disconnected the battery ground and removed that wire, which presumably runs to a module somewhere for this "security system." Hooked the battery back up, turned the key on, and everything that had been screwy worked perfectly. Got the radio back, got the A/C back, got all my gauges back, no crazy dinging or random assortments of lights on the dash. PDLs and window switches work again. Interior lights actually go off when they're supposed to and the info center doesn't say "Door Ajar" when the doors are all shut. It's like having a new car.

I can't tell any ill effects from having this other "foreign" electronic system disconnected. If I ever find the other end of it, I'll pitch the whole thing in the trash.

A couple of weeks ago I'd asked a dealer tech about it, and he said he thought the battery was the likely culprit; had he known about this "system" that may have been the first thing he tried, too. It must have had some internal problem that gave the rest of the car's electronics fits. I really started to suspect it (as opposed to the BCM) because of the fact that things seemed to work normal until a few seconds after the engine was running.

When I bought the car, it had this third-party system's remote on the keychain, not an OEM remote (wish I had that instead). It did not come with any instructions, and after buying the car I tried to research it on the net to figure out what the various key combinations were so I could use it, but apparently it's one of those "programmable" deals and I had no interest in sitting around trying to solve it for such a low payoff. I just don't need my car to honk at me when I want the doors locked.

Anyway, thanks to those of you who made suggestions.

Ha. Not so fast!! The car worked fine for a couple of days after I unhooked the third-party remote's power cable. Then it was back to the same old problem. The only other thing I had done was temporarily disconnect the battery's ground cable while I did that.

Since then, I have found that I can make the car work normally again temporarily just by disconnecting the battery ground for a couple of minutes and reattaching it. But the problem always ends up coming back. I took the battery out and had it tested. It tested good. I put the battery back in and sure enough, the car acted normal for a while. It's almost like something is being allowed to discharge when the battery is disconnected and somehow that's permitting things to work normally for a bit. Often, I can shift into reverse and that will cause the car to work normally again, but only for a few seconds.

I found a group of grounds under the rear seat and another pack of them under the plastic trim on the driver's door jamb...those all look good.

I still haven't figured out where the actual third-party remote's electronic module is.

Bottom line, I'm still looking for the REAL answer.

When I bought my BCM, it was only about $100. I ended up not even using it. It just sits on my shelf.
One dealer told me it needed "programing," two said, no. I plugged it in, worked with no programing.
If you ever get a new BCM, don't fall for the "programing" trick.

Chris.

Finally, I have a resolution to the problem. Obviously I had been getting nowhere--slow. I took the car to a GM dealer. At first they did not want to tackle it because of the third-party remote wiring making everything "nonstandard." (Note to self: Do not buy used cars with non-factory wiring added.) But in the end, they were able to make a diagnosis. A new "Rear Integration Module" (RIM) took care of it.

On the 'net I have seen this device called other things...a "BCM" or a "BCC." GM P/N was 10383937. It cost about $150, and with labor, the whole thing totalled out at $300, which was I thought was pretty fair, and much less than I had feared this adventure might cost. You can get these "RIM"s for a lot less on eBay and other online places, though they may be used / salvage parts--and may or may not need follow-up programming. Apparently this "RIM" lives behind the rear seat in the upper driver's side corner.

Sure is nice to have the radio back after six months!

Anyway, hopefully this story will help save some hassle for the next person in a LeSabre when the dashboard lights up like a pinball machine and the interior electrical system appears demon-possessed.