FC alternator concern.
 

Hey Folks, I have a 90 n/a fc rx7 and my concern is at times I have noticed the volts gauge reading @ 14 volts and sometimes alittle over 14 volts. It that alright? What do you think?
I think its not, so what I do is turn on my headlights, interior fan, radio etc and thus brings the volts back to 12.5 volts or so. Are there any long term negative effects if I don't take this measure of turning on the accessories and bring the volts down ? This mostly happens in the morning or after the car has been sitting a day or 2 without driving.
Thanks.

I'm pretty sure a healthy charging system outputs 14-14.5V. An output of 12V would mean your either heavily loading the system or running straight off the battery. Either way it sounds like your charging system is in good shape so I wouldn't complain :)

That's normal for a stock FC alternator.
If you haven't figured it out by now, the stock FC alternator SUCKS.


-Ted

14v is fine. I'd check it at the alternator/battery to see what it really is though since the gauge may be off. My gauge always reads 12 or under yet I haven't had an issue in 10,000 miles.

Okay good. I thought something was broken. oh LOL old cars.

14 is spot-on. Granted, I run a pair of 12" subs in the back of my car, but mine sits around 12.5 to 13. Sometimes down to 11.5 with the bass up high

I'd kill for an alternator that didn't fall below 12.5.

You and me both. I'm looking in to it as I don't want to have to deal with my charging system as it currently sits and may infact tax it with some of the modifications I have planned. I need to locate a parts distributor for the FD alternators so I can rebuild the one I have.

I have a FD alt sitting in my garage. Used it for about 2 years and it always did a fantastic job on my stock 87 GXL, putting out a solid 14 volts at idle when pulled from my car.

Gotta say that I was impressed with it. The car had a s4 alt on its last legs and simply was hell on the battery. The FD alt cured it and was my first mod. But after swapping to a Taurus 2-speed E-fan, the FD alt was getting pushed a bit more than I felt comfortable with. One day of it was all that it took to convince me to pull it to prevent damage and grab the alt from the same Taurus that the fan came from.

It's an original Mazda one too, no autozone 'rebuilt' crap. If you're interested, pm me and I'll give you a great deal on it.

Rich, goodfella, has some beefy ass re-wound FD alts available as well.

I've never over worked the FD alt I have, a fresh bosch unit from carquest, but I don't run much in the way of amp heavy items other then my dual e-fan.

I'm running a 10" sub, amp, taurus sho e-fan, gauges, and other goodies on my FD alt, works fantastic. Seeing 14V at startup isn't anything unusual especially if that car has been sitting for a few days. The system is sensing that the battery is slightly low on charge and is full fielding the alternator so it brings the battery back up to life. You may even notice it charge high like that on colder days as well.