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Discussion Starter #1
So I was in the process of getting my miata ready for a brisk drive and I notice the dash flickering and the idle was a bit iffy, so I pull over and turn everything off, car starts right up no problem... Its slightly surging in traffic and the idle dropped a few times but nothing causing it to stall... Anyone have an idea what it may be? Something say alternator to me....
 

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It could be the alternator or a battery terminal came loose. Sounds basic though. I wouldnt worry too mush as some poking around will most likely lead you o the solution. GL and keep us posted on progress.
 

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Check the battery voltage.
Check alt tension.
Check alt output.
Check grounds.

That's what I would start with.
 

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Discussion Starter #9
thanks guys i'll get on it tomorrow at work..... Maybe a ground somewhere is nasty or something is slipping... i checked the tension on the belt and its fine, I also cleaned the terminals and they were both tight a bit dirty but tight.... I forget how to check the alt output lol ( dont flame me)....
 

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same thing happened to me, was the Neg. post holder doohicky loose. You know, with the wire and the round thinger that has a bolt going through it with 10mm nut on the other end. DOOHICKY.
 

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Discussion Starter #11
Lol I'll check it in the morning DJ thanks for the DOOHICKY advice lol
 

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Similar thing happened to my car, turned out the ground that is on top of the intake manifold near the throttle body was loose. Check that one and the body ground on the drivers side of the motor near the firewall.
 

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To check output pos end on alt power and neg end on the 12v source plug. (Blue open plug on driver side for NA) 13v plus it's good. But can't be too high.
 

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Discussion Starter #14 (Edited)
I checked the car out today all the grounds and cables were tight, I did a load test and it spiked @ 15.41 volts and would come back down to 13 and change, my boss told me the regulator in the alternator is shot which is why the voltage is spiking, so the alternator is to blame -___-... 123 bucks and it'll be swapped out next week....
 

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15 is a little high there.

Edit: I am not sure what cars it is, but I know output is controlled by ECU in a MSM.
 

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I checked the car out today all the grounds and cables were tight, I did a load test and it spiked @ 15.41 volts and would come back down to 13 and change, my boss told me the regulator in the alternator is shot which is why the voltage is spiking, so the alternator is to blame -___-... 123 bucks and it'll be swapped out next week....

Ermmmm.... what year is your car? Your boss very well may have steered you wrong.
 

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15 is a little high there.

Edit: I am not sure what cars it is, but I know output is controlled by ECU in a MSM.

Yep, you beat me to it.

And yes, it is. AND IT DRIVES ME FRIGGIN' INSANE.
 

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Discussion Starter #20
Its a 99... I learned that when I traced the harness back to the source.... its constantly spiking so replace and see what the deal is afterwards i guess...... i hate shotgunning -__-
 
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