Alternator voltage low. Options?
04-28-17, 08:50 PM
#1
Alternator voltage low. Options?
The seven decided not to start today after I drove it a bit. The solenoid would kick but the starter wouldn't crank. Push started it and drove it home. When I got it home I checked the output voltage of the alternator at idle and it's 13.5-13.7volts. From what I understand it should be 14.1-14.7volts. Looks like mazda doesn't have any in stock. Anyone have recommendations for either a DIY rebuild kit, or anyone have experience with a -gulp- autoparts store unit? I know IRP offers their 140amp unit, I'm just not sure I -need- that. The sooner I can procure one the better as well.
Matt
Matt
04-28-17, 09:35 PM
#2
The seven decided not to start today after I drove it a bit. The solenoid would kick but the starter wouldn't crank. Push started it and drove it home. When I got it home I checked the output voltage of the alternator at idle and it's 13.5-13.7volts. From what I understand it should be 14.1-14.7volts. Looks like mazda doesn't have any in stock. Anyone have recommendations for either a DIY rebuild kit, or anyone have experience with a -gulp- autoparts store unit? I know IRP offers their 140amp unit, I'm just not sure I -need- that. The sooner I can procure one the better as well.
Matt
Matt
04-29-17, 10:50 AM
#4
While I have not tested the amperage output, I do have a whining from my speakers under heavier electrical loads. In previous experiences, this has also been an alternator issue. A smaller parts store in the local area was able to get me the only Denso alternator left in the valley. With that I'm gonna go grab it and throw it on and I'll report back if this fixes my low voltage issue (and battery charging issue).
Matt
Matt
04-29-17, 01:20 PM
#5
I ended up buying one of these from ebay.
direct swap and good fit,only thing is you need to make sure that you swap your oem pully onto thenew alternator as the new one is bigger and run some heaviergauge wire from the alternator post to the fuse box
also my windows roll down lightning fast after this
HIGH OUTPUT FOR MAZDA RX-7 R2 1.3L 1308cc 93 94 1995 NEW ALTERNATOR 200 HIGH AMP eBay
direct swap and good fit,only thing is you need to make sure that you swap your oem pully onto thenew alternator as the new one is bigger and run some heaviergauge wire from the alternator post to the fuse box
also my windows roll down lightning fast after this
HIGH OUTPUT FOR MAZDA RX-7 R2 1.3L 1308cc 93 94 1995 NEW ALTERNATOR 200 HIGH AMP eBay
04-29-17, 02:34 PM
#7
Constant threat
This thread made me get out my Service Manual and review. Good stuff in there.
I see our stock alternators put out 100 amps at 2500 - 3500 rpm...I wonder what the amperage is supposed to be, or if it changes much, at idle?
I bought a new Kenwood amp the other day because I got a good deal on it, but it draws 54 amps of power alone. Thinking about going with an IR Performance upgrade...just for ***** and grins.
I see our stock alternators put out 100 amps at 2500 - 3500 rpm...I wonder what the amperage is supposed to be, or if it changes much, at idle?
I bought a new Kenwood amp the other day because I got a good deal on it, but it draws 54 amps of power alone. Thinking about going with an IR Performance upgrade...just for ***** and grins.
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04-29-17, 02:54 PM
#8
Per FSM, voltage at terminal B should be 14.1-14.7 at idle. My voltage was 13.5-13.7. My PFC read the same results as my multimeter. It was 80*F when I was troubleshooting. Scored them baby from a Parts Authority nearby me.
Waiting on a belt to show up at 430 since mine had a cut in it. I'll let you know if this is the fix. But I'm confident it is.
Matt
04-29-17, 07:19 PM
#9
The seven decided not to start today after I drove it a bit. The solenoid would kick but the starter wouldn't crank. Push started it and drove it home. When I got it home I checked the output voltage of the alternator at idle and it's 13.5-13.7volts. From what I understand it should be 14.1-14.7volts. Looks like mazda doesn't have any in stock. Anyone have recommendations for either a DIY rebuild kit, or anyone have experience with a -gulp- autoparts store unit? I know IRP offers their 140amp unit, I'm just not sure I -need- that. The sooner I can procure one the better as well.
Matt
Matt
Have run both, and have never had over 14v in any operating range (idle, revving, etc.)
