ABS light on - I checked several things, any clues?

[roadster]

The ABS light came on yesterday and stayed on.
I checked the brakes - new pads installed about 1 month ago on all four corners, fluid reservoir full.
checked the sensor wires, they look ok with no worn spots
pulled off battery terminal to reboot the computer.
Checked fuses - both maxi and mini - no help.
I also disconnected the sensor wires at the plugs and reseated them.

Is there a way to check the sensors?
Also there only seems to be a sensor for the front rotors. I can't see any electrical connection for rear sensors.

Any suggestions?

TIA!!

97 XLT 5.0 V8

 

[TPLYNCH]

The rear sensor sits on the rear differential.

 

[rameyer]

I don't know if the 97's have them, but my 94 was having problems with the relays in the engine compartment. I replaced all of them and that took care of several problems, including the ABS light.