How do you change an alternator belt on a '93 Prelude Si?
well I'm not quite sure on a '93 but on my 86 Si there is a hard as hell little bolt in an arced slotted bracket. if its been on a while you might have to loosen it alot or take it off all together. Once you have done that then simply take the belt off. (first you might have to take off the power steering and AC compressor belt. second as i said if its been on a while you'll have to pry it some to get it to swivel.) After the belt is off put the new belt on and then put the adjustment screw in until just slightly snug(you still want to be able to move it at this point CRUCIAL!. now here is where you need either an extra person with strength and someone to tighten the bolt. get a something you can use to pry the alt. (possibly what you used to pry it loose) till the belt is fairly taught. however be very careful on how you pry at it so as not to bust it. Also over tightening it may harm the pulley which is bad. the proper tension would be when you push on the belt with firm but not hard pressure it will give about a quarter of an inch(after you've tightened the adjustment screw. once you get proper tension go ahead and tighten down the screw as hard as you can use a cheater bar for extra leverage would be a good idea. put the rest of the belt you took off back on (p/s and A/C doesn't work on mine so i left them off) and start the car. if it squeaks its to loose(don't use belt dressing) just loosen the screw and pry it more taught and re tighten screw and try starting again. once you get the whole bit done drive the car around for about 20-40 minutes because the belt will get warmed up and also stretch a little bit. (it took mine about 3 hours to get completely worked in) after that recheck the tension the deflection of the belt should be between 1/4 to 1/3 of an inch with firm pressure as mentioned below. now enjoy a better MPG a better charged battery and a squeak free drive.
NOTE!make sure you have the belt seated in the grooves respectively you don't want the thing fly off at 3k RPM's and getting wrapped around other pulleys and totaling your car.