Hello! Really happy to have found this forum. I've been posting on various Honda forums for about a year now and recently purchased a 1991 Mazda Protege.

I read a few posts on similar issues and nobody seems to have posted a resolution. I'm really afraid that I will never find the answer to this problem.

I purchased this car knowing there was an electrical issue, was told that it would need a new alternator. First thing I did was go out and by a new Hitachi alternator. I took the old alternator out and put the new one in, started the car up and to my surprise, the battery was nowhere near 14 volts.

So, I assumed the battery voltage wasn't sufficient and the altnerator was being over worked. I went out and picked up a battery charger, chargers the battery to 12.4 volts, took the charger off, let the battery sit. Came back 30 minutes later and the battery had dropped .4 volts. Is this a bad battery issue? Even if the battery is dead, shouldn't the alternator still be charging it? The voltage of the battery did not drop below 12volts, even over night. It seems to be holding a charge, somewhat. The battery is new, according to the previous owner.

Now, here is what I found weird. I placed one prong of my voltmeter on the positive terminal of the battery. The other prong went to the neutral of the alternator (the car was off), I got a reading of 12v, good. Now, I took one prong of the voltmeter and put it on the positive terminal of the battery and put the other prong on the positive lead of the battery (the wire you tighten to the battery terminal), and I got a reading of 12v, weird. Wouldn't this indicate a short?

 

disconnect the battery and reconnect it negative first, then positive. if there is a spark, there is a short. if there is no spark, there still may be a short that isn't as noticable. check to see if the battery loses more voltage in the car or out of the car.

this could be something as simple as an iffy ground wire that is making a connection long enough to start the car, but not allowing it to recharge the battery.

 

I don't see a spark but I hear a short (that tell tale 'click').

I had both alternators (new and old), as well as a battery tested, all 3 are good. Good news is I returned the new alternator and saved myself $300. Bad news is I'm at a loss for what to check next. My buddy told me that since the alternator is good, the magnetic field it needs isn't being setup correctly?

The car is a 1991 Mazda Protege 1.8L DOHC FWD. The radiator has been replaced and I noticed some wire splicing in that area.

Please help.

 

shorts are really difficult to find sometimes. the only thing that i can recommend to get it 100% is to spend all night pulling fuses and relays while installing and removing the battery. unless you can find where some wires have either been pinched or spliced, that i really the only other good way. most mechanics don't like anything other than basic wiring and will just blow you off saying that they don't know what the problem is.

 

The next thing your buddy will tell you is that the flux capacitor needs replacing.

 

or the muffler bearings are out.