hey just i still get the problem like many rx7 owner of battery not charging when all accessories are on, if the blower wiper and defroster and the headlights are on it fall bellow 12 volts and it almost shuts down

im gonna get my alternator upgraded,
so what amount of amps would be good to increase to for all my accesories to be on

 

My alternator was on the outs and slowly started to decline on volts to barely staying above 12.4 volts ..you need 14.4 volts, I had a spare stock alternator and popped it on ..Bingo 14.4 volts. problem solved!

 

Unless you're running a big sound system or some other big electrical drain, a stock one should be fine. Getting it re-wound for higher amperage is much more expensive than a stock replacement. If you need more amps, look into the FD alternator. Or 130 amp taurus alternator.

 

my car does not stay at 14.4 volts its more between 12 and 13volts, is that bad?
the alternator is new, only had it for 8months in the car but i only get the not charging when i have all the accessories on, it gets really foggy in the rain and i need this fixed
i replaced both battery cables hoping it would increase the voltage but didn't
i have checked all my grounds and their all good and cleaned, is there anything else i should check before deciding to upgrade the alternator, do you guys think i might have something draining power

 

At idle, under 13 volts is common. Driving down the road, you should be between 13.5 volts and 14.

Regardless, this situation is what drives the popularity of the FD alternator.

 

Get it rebuilt for higher amperage. Im doing that to mine this weekend, and did it on my last 7 with no problems. Best part is, u dont have to mess with the wiring or using spacers, ect, ect, u just bolt and plug the sucker up.

a local starter/alternator shop quoted me $110 to do it. not bad imo.

 

arsinal4496- oh really how many amps did you increased it to be fine

hozzmanrx7- hey hows it going, unfortunately it doesn't increase at all its confusing
s

 

they claim to put out 100amps. seems to be the highest output u can get from this alternator?? i called several places before and they all told me it'd increase to about 100amps to 110amps.

i noticed a difference on my last seven. i had no issues even with the taurus fan on at night with the lights on, defrost on, rear wiper, and stereo on (stockish stereo).

if your amps arent increasing when u start moving. its usually a good sign that the alt is toast.

 

Hey True,

If the voltage doesn't increase, then you simply have a bad regulator in your alternator. Just because it's only a few months old doesn't mean it didn't crap out on you. Replace it soon before it drops further.

And, from experience, having your S5 (or S4 for that matter) alternator rewound for more amps has it's downside as volts will be even lower at idle everything else remaining the same. So you'll be running in part on the battery at every stop.

 

hozzmanx7- do you recommend just upgrading to a fd alternator?
what else do i check to make sure its the alternator and not a power draw from somewhere

 

Switching to an fd alternator helped my car out a ton. If you have an s5 it's a direct swap, takes all of ten minutes to put it in.

 

The FD alternator worked great in my S5 as well. The only issue was that I had to "message" the UR steel strut bar's cross brace a bit for added clearance.