I did my research and discovered that when the speedometer on this thing intermittently drops out, it's most likely the vehicle speed sensor mounted on the automatic transmission. I dutifully secured a replacement, including the little spindle, pulled the old one out and put the new one in. Now the speedometer doesn't work at all. So I guessed maybe I got a bad one. I put the old one back in, and it doesn't work at all now, either. The only oddity I can find is, one of the mounting bolts almost appears to be stripped; it won't tighten all the way down. But the sensor appears to be solid on the casing and the other bolt is nice and tight. Other than that, I have no idea what's going on here.

Any thoughts?

Disconnect the negative battery cable and thoroughly check out the 2-pin connector. Was the replacement sensor new or salvage?

Disconnect the negative battery cable and thoroughly check out the 2-pin connector. Was the replacement sensor new or salvage?

Salvage.

Was it an exact Honda part no. match?

Was it an exact Honda part no. match?

As far as I could tell, yes. And I snagged the little spindle and replaced that, also.

Disconnect the negative battery cable and thoroughly check out the 2-pin connector. Was the replacement sensor new or salvage?

A couple of things: it's a 3 pin, not a 2. They're black, yellow, and blue. Also, is that possibly-stripped bolt a big concern, or will the other one hold it sufficiently? It appears to be solid, but...

When checking these pins with a continuity tester, I have continuity across black and yellow, continuity across yellow and blue, nothing across black and blue. I'm guessing that's how it should be, but am thoroughly willing to be corrected.

Yes, 3-pin: Black (ground), Yellow (power), and Blue (signal). Check for codes and check all under hood and under dash fuses with a test light or multimeter.

Yes, 3-pin: Black (ground), Yellow (power), and Blue (signal). Check for codes and check all under hood and under dash fuses with a test light or multimeter.

All fuses check out. I don't know how to check codes on this thing. And what about the bolt? I took a closer look and the hole is definitely stripped.

Yes, I would fix the stripped bolt.