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Volts dropping in high heat? bad alternator??

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Old 07-21-2012, 07:12 PM
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Default Volts dropping in high heat? bad alternator??

ok here is my problem when I first start my car and get going the volts on the guage are over 13 probably about 14 or so. after a while of driving when everything gets warm they drop to well under 13 around 12 or so and right on the orange warning line and the car does seem to run a little funner after that, Never dies though.

This only happens during the HOT part of the day, driving at night is no issue.

could the heat just be killing my alternator slowly? Im on a stock alternator and stock connector still I thoguht about hot wiring the alternator directly to the battery could this solve it?
Old 07-21-2012, 08:45 PM
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try a truck alt
Old 07-21-2012, 10:24 PM
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maybe check your grounds .
Old 07-21-2012, 10:32 PM
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grounds all look good any specific one to check? and why would grounds get worse during heat? it only happens once the car gets warmed up everytime I start it up it starts at 14 volts but once warm goes down to 12, it does rise and fall with rpms though
Old 07-21-2012, 10:39 PM
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I plan to switch to a 145 truck alternator. just wondering if this could possibly be in the wiring or the connector or the alternator dying.

also when I hotwire it to the battery where should I bolt the wire to the alternator at? and should I still leave the normal plug in?
Old 07-21-2012, 10:46 PM
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Switch to the truck alternator. It's well worth it trust me my car did the same thing once the alt. got warmed up it would drop volts when I wasn't moving
Old 07-21-2012, 11:24 PM
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ok I understand this I do plan to do this but still knowone has answered the origial question, I would like to know if this is a sign of the ALTERNATOR going out. and also i would like to know about the proper way to wire it directly to the battery. I already said I plan to get a 145 truck alternator but that dont answer my questions I want a legit answer on if this thing is going to die on me. just cause I get a new alternator dont mean it will fix it either it might but it might not. there is a reason why it only loses volts once warm
Old 07-21-2012, 11:41 PM
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well I did some research and it could be a number of things so this is going to take some diagnosing. I will check the grounds as recommended, it could also be the battery from what I read up. but its a brand new optima. I have also read up high rpm performance cars that spin 7k and burn them up as well LOL.

I really do want to do the direct wire to the battery on my car as well, is there anywherre specific I have to run the cable and attach it to the alternator? I know old alternators have the little screw on the back but do ours as well I have never looked
Old 07-22-2012, 12:17 AM
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https://ls1tech.com/forums/generatio...lternator.html
Old 07-22-2012, 12:18 AM
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https://ls1tech.com/forums/generatio...-failures.html
Old 07-22-2012, 12:49 AM
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I of coarse have read those threads and yes they mention the truck alternot and the 244.

I am pretty sure I have mentioned I DO plan to use a truck alternator but just because a altenator drops volts when heated DOES NOT MEAN ITS A ALTERNATOR!!. also these posts do not answer the questios I am asking.

The questions I am asking is SIMPLE,

WHERE DO I ATTACH THE WIRE TO THE ALTERNATOR TO HOOK DIRECTLY TO THE BATTERY!!.

If you are not going to actually answer the question please do not reply just to up your post count. and your obviously not reading anything after the first post since you simply suggest a truck alternator which I clearly mentioned I already know about sorry to be rude but common
Old 07-22-2012, 02:37 AM
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post 8 in the alternator thread shows the stock attachment point on the back of the CS130 and AD244 for the stock pos lead that goes to the batt

post 29 shows a pic of where i placed the welding wire in addition to the stock batt wiring for my big 3 upgrade

post 5 is a close up of the AD244 batt lug on the rectifier
Old 07-22-2012, 12:39 PM
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ok I think I see now, so i just run a wire from that post strait to the battery? thanks for clarifying it for me I did look through the post just saw alot of bolts on the back of those alternators with the covors off. what guage wire you recommend?
Old 07-22-2012, 12:40 PM
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I assume on the stock alternator the bolt is the one towards the center on the right?
Old 07-22-2012, 04:00 PM
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Originally Posted by 82cetuner
This only happens during the HOT part of the day, driving at night is no issue.

could the heat just be killing my alternator slowly? Im on a stock alternator and stock connector still I thoguht about hot wiring the alternator directly to the battery could this solve it?
Sure. Your alternator has a voltage regulator in it, which is the part that... regulates the voltage. Its solid state and if its bad, the internal components of the regulator can expand when heated, short internally, etc.

The fix for a bad alternator isn't a truck alternator. Its just a new alternator. (Or you can tear it apart and install a new voltage regulator if you are enterprising. You can check out Alternatorman on YouTube for some how-to's.)

Other things to watch out for:
- If heat is the issue, a bench test an an auto parts store may not catch the problem.
- When its hot outside, we tend to run the A/C more. The A/C is taxing on the engine, etc. so you'll want to confirm the problem is only due to temperature and still comes up no matter if your A/C is on or not.
Old 07-22-2012, 10:09 PM
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well I drove the car with the A/C off and the radio off, I noticed a drop off once the fans kicked in so I guess the alternator is just old and weak and once I turn on the radio, lights, A/C it just cant keep up. looks like il be doing the 145 truck upgrade sooner than planned
Old 07-23-2012, 06:05 AM
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Originally Posted by 82cetuner
well I drove the car with the A/C off and the radio off, I noticed a drop off once the fans kicked in so I guess the alternator is just old and weak and once I turn on the radio, lights, A/C it just cant keep up. looks like il be doing the 145 truck upgrade sooner than planned
Sounds normal. What voltage do you see when everything is on?
Old 07-23-2012, 09:35 AM
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12 and it sits in the orange, car never dies but does seem to run a bit roupher
Old 07-23-2012, 10:22 AM
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Orange is definitely bad.
Old 07-23-2012, 10:24 AM
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yeah i figured that much but it never dies and never drops below 13 i the ac is not on im just going to do a 145 and hotwire and call it a day


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