I ordered one sensor on line for $30 and got the wrong part. Second time around and I'm a little more careful and lots more skeptical . . .
I get a quote from Auto Zone for $60 and the picture looks right but that's a lot of money for something that (electrically speaking) is no more complicated than one pickup for an electric guitar, and guitars use 6-18 of them per instrument.
I'm beginning to think this is something I could make myself, if $60 is the other choice. People Do make their own guitar pickups, it isn't that hard.
The defective one has a part number molded into it (P/N4485165) I go on line with that number, and I find it linked to Ford part number F85Z9E731. Aha! Chrysler, Ford, and Mazda, it turns out, use essentially the same part - they bought "their" ABS systems from the same source, they didn't design them "in-house."
I order the generic aftermarket part for $11.87 - Dorman P/N 970-012. The Dorman web site gives a list of applicable vehicles. It's on my
91 Dodge Ram and working fine.