Mystery Power Drain????
 

So for a few days now I've been having a strange charging problem with my alternator. About 2 weeks ago the voltage warning light came on in my dash. (89 CRX)

OKay this didnt surprise my much as a year ago prior I had fried my Alternator (bad wiring) and replaced it with an alternator with about 150k+ miles on it from an old engine I had laying around.

But it doesnt seem to act like a dead alt. Here is why..
1. When it stops working I see a noticeable power drain (lights dim/interior fan slows/stereo deck shuts off) But a quick blip of the throttle (5k + RPMS seems to do it) sends everything back to life. Power is regained almost instantly.

2. The Alt seems as to only stop working at freeway speeds. At idle and driving around town it seems fine, until the enigne warms up a bit.

3. I replaced the belt (wishfull thinking) and everything seemed fine for a day or so, then it started all over again.

If I had to guess I would say that it was a hung brush on the alternator...But I am worried that it might be draining power elsewhere...so any ideas as to what caused this??

Oh yeah car info: 89 CRX with ZC engine

Re:Mystery Power Drain????
 

first test your alternator output voltage.. should be around 14v. If not do a voltage drop across the cable. if it drops more than .5 volts replace the cable. if that all shecks out.... do an amperage draw test. if you have access to an ammeter, check the output amperage with a full load on the alternator( turn on stereo, lights, wipers, etc) and compare to its rated out put.... if it fails that test replace alt. (it should make charging voltage and amperage at about 2000 rpm so when running voltage output test rev the engine to about 2000 rpm)

Re:Mystery Power Drain????
 

what battery is in there? the alt isnt spinning fast enough at idle, cruising etc and juice is taken from the bat to keep up w/ demands.