Battery randomly dying

LS WUT

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What’s going on gents. So now that I’ve got my 13’ Shelby back I’ve been driving her around. I go back and forth. I more recently had a battery die on me, and I had to bump start her because I was in the middle of the boonies by myself. Anyways, while driving I noticed my radio cut out, as if it lost a fuse or something. A little while later it came back on. As I was coming to a stop sign the idle dropped to around 500-650. I thought it was going to stall. I get to my next stop, turn the car off And as I’m gathering my paperwork I notice my dome light is a little dim. So I was like maybe my battery is really low, and the alternator isn’t charging it? I try to turn the car over. Nothing but clicks. I finish my route, bump start that beast myself because race legs. Anyways I tested the battery, it showed 345 CA not the 580. So I changed the battery. All is well, well once again my battery died on me. I checked the alternator output and it showed good. Wondering if anyone has any insight, or thoughts? Possibly the alternator is working intermittently ? Mind you this cobra is bone stock, no aftermarket radio, gauges, etc. thanks in advance boys.
 

DSG2003Mach1

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how are you verifying the alternator is good and what did it show? It also helps to test after being at full operating temp for a bit as voltage requirements increase and alternator output naturally drops a little.

If may be helpful to pick up something monitor voltage via the OBD 2 port so you can see if starts falling off.

check your battery terminals are tight, no corrosion and I'd double check the grounds for shits and giggles
 

03' White Snake

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I had an intermittent alternator issue. Was fine when cold, as soon as it got hot, output would dropped down to 10.5. Not enough to charge or keep the car running. Tested fine at Autozone too. I'd replace the alternator.
 

AFLOCOBRA

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I had an intermittent alternator issue. Was fine when cold, as soon as it got hot, output would dropped down to 10.5. Not enough to charge or keep the car running. Tested fine at Autozone too. I'd replace the alternator.
check your grounds make sure theres no corrosion either on both temrinals too. Get you a multimeter measure the voltage car off and on running should be in the ball park of 13volts DC obviously.

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LS WUT

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Terminals are very tight, no corrosion. The battery, alternator was checked when it was cold. Not at operating temperature. I’ll make sure to check that. I’ll also check the grounds, and such. I’ll get it up to temperature today and give her a look. As for how it was checked, my buddy works for AAA, so he’s got a box that shows output, cranking amps, etc. I’m gonna go with the alternator being a pooper. I’d presume it was stock as well. Previous owner who was the original mind you told me all was as is, never replaced. Even the OG motorcraft battery. Which I kept out to preserve it. I’ll keep you boys posted, thanks again for the replies. Much obliged.
 

LS WUT

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Sorry for my delayed response boys. Been chasing other demons with that black one. Luckily I’ve got a 19k mile parts car lol. Just kidding, anyways. Turns out you guys were spot on as per usual. Cold start alternator is good. During operating temperatures it drops down to 11.1-11.3 alternator is No Bueno. Ordering a new one today. While doing such I noticed my A/C wasn’t blowing as hard as usual. So I swapped the blower motors. No change. It blows harder on A/C than Max A/C. Possibly resistor ? Anywho! Thanks gentleman, as usual much obliged for your knowledge.
 

LS WUT

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20BC546C-4C2B-4714-8B99-1DB3CBF4575F.jpeg

Thanks to this Ol’ Girl.
 

DSG2003Mach1

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Sorry for my delayed response boys. Been chasing other demons with that black one. Luckily I’ve got a 19k mile parts car lol. Just kidding, anyways. Turns out you guys were spot on as per usual. Cold start alternator is good. During operating temperatures it drops down to 11.1-11.3 alternator is No Bueno. Ordering a new one today. While doing such I noticed my A/C wasn’t blowing as hard as usual. So I swapped the blower motors. No change. It blows harder on A/C than Max A/C. Possibly resistor ? Anywho! Thanks gentleman, as usual much obliged for your knowledge.

Id say fix your voltage problem before you go chasing your tail on any other electrical components
 

AFLOCOBRA

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Sorry for my delayed response boys. Been chasing other demons with that black one. Luckily I’ve got a 19k mile parts car lol. Just kidding, anyways. Turns out you guys were spot on as per usual. Cold start alternator is good. During operating temperatures it drops down to 11.1-11.3 alternator is No Bueno. Ordering a new one today. While doing such I noticed my A/C wasn’t blowing as hard as usual. So I swapped the blower motors. No change. It blows harder on A/C than Max A/C. Possibly resistor ? Anywho! Thanks gentleman, as usual much obliged for your knowledge.
if you got the coin get yourself a mechman.

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