Spark when connecting battery caused by... bad ground?

I was helping a friend with her car and it turned out she had an old battery that wasn't any good. The closest place to get a replacement was AutoZone so we went in. We conducted the transaction, and because I'm lazy, we had the guy behind the counter do the install for her.

When he put the new battery in, the Old Coot Behind The Counter declared that the car had a bad ground. When I asked him what made him think that, he told me it was because when he connected the battery cables to the new battery, he got a little spark. He indicated that the ground strap that went from the fender to the hood was broken and could be causing that spark. Oddly, he also connected the negative terminal first and then positive and I really thought that the positive should be the first to connect and the last to disconnect.

I was pretty sure that spark is created because there's always something "on" in the modern automobile and the current would attempt to complete the circuit by arcing through the air as the cable got close to the terminal of the battery.

So, while I'm fairly certain the old coot didn't know what he was talking about, I'm also willing to admit that I don't know what I'm talking about. So, oh great keepers of the knowledge, learn me: Does a small spark when connecting the battery cables mean the car has a bad ground? Has everything I thought I knew about car batteries been wrong all these years?

EDIT: Sonofa... I wish you could edit post titles. ConnectING not connected...

That would be news to me.

99.99% of cars in use today have something that draws power constantly.

The spark you see when hooking up battery leads is very similar to how a spark plug works. That small amperage draw is literally trying to jump the gap as it gets small enough.

The old coot at Autozone is a dimwit.

EvanR wrote: 99.99% of cars in use today have *something* that draws power constantly. The spark you see when hooking up battery leads it very similar to how a spark plug works. That small amperage draw is literally trying to jump the gap as it gets small enough.

What Evan says.

Okay, that makes me feel better. I was pretty sure I knew how electricity works (well, the basics at least), but buy was that guy sure of himself...

wae wrote: I really thought that the positive should be the first to connect and the last to disconnect.

That's how I always do it.

EvanB wrote:

wae wrote: I really thought that the positive should be the first to connect and the last to disconnect.

That's how I always do it.

That's also literally how they tell you to do it when you go through AutoZone training. Its like the 3rd thing they told me.

The negative off first, on last is just a safety thing. It really doesn't make any difference to the car, but it sure makes a difference to your eyeballs when you ground out the positive post with the wrench and blow the battery up in your face.

wae wrote: So, while I'm fairly certain the old coot didn't know what he was talking about, I'm also willing to admit that I don't know what I'm talking about.

That's the difference between you and him.

FWIW, the guy's a moron. Also, the hood ground strap is for RFI reasons. (Really)

In reply to Knurled:

I always wondered what the hood ground strap was for. It seems like it would be grounded well enough through the hinges for it to have an effect on RFI.

In reply to Derick Freese:

You'd think, wouldn't you? But in some applications, when that strap breaks, you get staticy radio.