Replaced 2011 Buick Regal battery, Now NOTHING works

The battery on my 2.0L turbo Regal was dying. I nursed it along for a couple of days with a jumper box and an overnight charger. I gave up when it would no longer accept a jump. I bought a new H6 battery and installed it. Imagine my surprise when the car would not start, In fact it will not even crank, nor can I remove the key from the switch, or get it out of park to push it aside.

Yes, the original battery was quite dead. It will not take a charge. The new battery is good. It handles a 100 AMP load for ten seconds from my tester without dropping under 10.5 volts.

I’ve installed dozens, it not hundreds, of batteries and never had anything like this happen.

What did I do wrong, and how do I fix it?

You might want to read this.


First off, double check the polarity is correct. Not just by the label on the battery, but by measuring with a volt meter. It is possible to charge a battery backwards, reversed polarity, happens with a new battery sometimes. Beyond that, have you tried disconnecting the new battery and let it sit that way overnight, then reconnecting? It might reset the computers enough to at least get the key removed and the trans out of Park.

If there is no power the brake shift interlock won’t operate, double check the battery connections.

I don’t think it’s physically possible to hook the battery up incorrectly. My testing it with the VAT 60 proves it is correctly charged.

The car has a plate that is an exact fit to connect the positive cable to the battery. I’ve never seen another one like it. That’s why is takes that rather special H6 battery. The positive cable going to the starter connects off of the other side of that plate, and goes directly to the starter. There are two 250 amp fuses and a row of 100 amp fuses attached to the metal plate. There’s a 250 amp fuse at the + post, and another 250 where the starter cable connects to it. As far as I can tell, all of the fuses are good as are the connections. The flat black 250 amp fuses have four holes in them, which I have tested with a test light. I don’t know if the four holes should each pass electricity, but two on one fuse do and two don’t . Should both sides be the same? If they aren’t, will they not pass any (or enough) juice to make ANYTHING work?

They call it a fuse box battery terminal. It looks like this

OK, that was weird, and a bit stupid on my part. When I checked if current was passing through the four 100 amp fuses to the side, I put my test light on the center post where the nuts screw on. There was current there. Ahhh, but not BEYOND there. Tightening the 8MM nuts, which I obviously didn’t do before, made everything work. Tightening ALL the connections, was the correct answer.

Everything works, even the radio presets. I did have to run the windows up and down so the “auto” system would work, but that was it.

Sorry to bother you all with something I should have picked up myself.

And it’s not even a Lucas electrical system…


Hooray! Good work! Been there, done things like that, got the t-shirt…
I’d bet you’re feeling pretty good right now, eh?

Good enough to have us all stop by for a celebratory beer, with you buying? :beer:
Just asking for a friend.


Glad you got it working again. Good debugging job there. Is there a reason you loosened those nuts in the first place? Is that required to replace the battery? It doesn’t seem like it would be necessary by the amazon link photo above you provided.

Or are you referring to the 2 nuts used to tighten the connectors to the battery posts?

No, the smaller nuts didn’t need to be removed. I thought the whole fuse plate needed to come off of the top of the battery. It does not. . Just pull the big nuts off, and pull the fuse plate aside.

as OP, you can change thread title. something like, "i forgot to tighten bolts. now battery wont work?