How to go about in OBD 1
You can't just clear the code by disconnecting the battery. There is a procedure, I'll get to that in a minute.
Generally if the ABS light is on, your ECU is trying to tell you it thinks you have a problem. You should check it out. Otherwise, it will just come on again. The good news is, you can start the process the same way you'll eventually clear the code.
First, connect terminal 4 and 13 of the OBD-II socket (under the dash in front of your left knee) with a jumper wire. (Those are the 4th from the left on the top and the fifth from the left on the bottom.)
Turn the ignition to on. You'll notice lots of flashing lights, but just pay attention to the ABS light. Normally, it should be rapidly and steadily flashing, twice per second. If it has stored a trouble code, it will instead be flashing a pattern that will coding a two-digit number. There may be more than one code being flashed out. It will just repeat the code over and over, so you have plenty of time to figure it out and write it (them) down.
NOW you can clear the codes. Just tap the brakes rapidly 8 or more times, about two taps per second. You don't have to jam on the brakes, just tap them enough to blink the brake lights. If you're successful, the ABS light should return to its normal fast blinking. Now remove the jumper wire, and finally turn off the key.
Now when you turn on the key, the ABS light should just do its normal light for three seconds and go off. If it comes back on, you still have a problem
You can look up the trouble code in the online tacoma FSM that you can find by googling, or you can post the code here and ask. Have fun!