91 chevy s10 blazer 2wd 4.3l

my speedometer doesnt work and my anti lick brake light stays on. i looked up the code with a paper clip and its a code 24. does a bad speed sensor cause the anti lock light to stay on? does this particular blazer just have the one speed sensor? or does it have a one at each wheel?

thanks

 

I 'm pretty sure theres one on each front wheel and one on the tail shaft of your transmission and the one on the tranny is the one thats bad . I say that because I am having the same problem but my transmission is not shifting right , but anyway I unhooked the two front ones and it didn't do nothing then unhooked the one on the transmission and the speedometer quit working all together . Mine works till 40 mph then goes to zero . Also the sensors on the front wheels are wheel speed sensors and the one on your tail shaft is a vehicle speed sensor .