Hi all, so I bought a 92 prelude with a charging problem. it cranks and starts (with a jump) and then runs ok for a couple minutes then slowly runs out of juice and stalls. I have checked the connections and grounds visually and they seem good. plus the same voltage is measured across the battery as is measured from negative battery terminal to alternator b post. the shop quoted the previous owners a new alternator so I went and got one off a 96 accord from a boneyard. it passed diode test so I bought it. when I was bench testing with a multimeter I found the prelude alternator had an ac voltage leak ~0.3V while the accord one did not. so I swapped it on (bolts up perfect) and the car is giving me the same problems. should I bite the bullet and buy a remanufactured alternator? or are there more tests I can run to be absolutely sure this is my problem. (battery reads 12.6 with car off btw).

 

What's the voltage output with the car running? Should be 14+.

 

It starts at 14.xx when connected to my running car via jumper cables and descends for a couple minutes until it reaches battery voltage and dies. I've measured the DC voltage at a bunch of different points in the circuit during this period and they all come back the same so I don't think I have voltage drop. I ordered the a remanufactured 96 accord ex alternator so I guess I'll just drop it in and cross my fingers... while we're here are these engines known to tick a little?

 

Yeah, your alternator isn't charging. Why not a Prelude alternator?

Anyway, yes a "sewing machine" sound is normal, but a distinct ticking could be a sign you need to adjust your valve lash.

 

hmm ok thanks for the tip, I'll be putting a valve adjustment in my maintenance to-do. idk I went with the accord one bc it puts out more power and is cheaper. I know it bolts right up bc I just put one in from the junk yard that didn't solve my problem.