Alternator is OK and Battery is OK - But still getting low Voltage reading
#1
06-09-2010, 05:00 PM
Join Date: Oct 2004
Location: French - Montreal Canada
Posts: 551
Rep Power: 43 
Alternator is OK and Battery is OK - But still getting low Voltage reading
Hi,
Some of you may have read my previous thread about my voltmeter reading.
Thinking it was the alternator, after 3 hours we were able to take it out and had it sent to a rebuilt shop. The shop called me thie morning and said that everything is fine, that it is like new condition and showing 13.8 volt no load and 12.9 volt full load (don't know what it means or what they are refering to).
The problem is the same. When I start my car, my volt meter is showing a steady 13.8 volts. However, once the car heats up, or after 10 minutes driving, it drops to 11.9-12.3 volts and then if I stop the car, it will not start again (due to a dead battery).
Neways, the battery is also brand new so I really need some opinions on what ca be wrong. All ground wires, including the battery one are tight to the chassis.
Thanks
Some of you may have read my previous thread about my voltmeter reading.
Thinking it was the alternator, after 3 hours we were able to take it out and had it sent to a rebuilt shop. The shop called me thie morning and said that everything is fine, that it is like new condition and showing 13.8 volt no load and 12.9 volt full load (don't know what it means or what they are refering to).
The problem is the same. When I start my car, my volt meter is showing a steady 13.8 volts. However, once the car heats up, or after 10 minutes driving, it drops to 11.9-12.3 volts and then if I stop the car, it will not start again (due to a dead battery).
Neways, the battery is also brand new so I really need some opinions on what ca be wrong. All ground wires, including the battery one are tight to the chassis.
Thanks
#2
06-09-2010, 05:27 PM
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Join Date: Mar 2008
Location: Montreal Canada
Age: 69
Posts: 2,807
Rep Power: 266 
Money down the drain.....
Why did you do that? 
I took some reading on my car and they were almost the same as yours and I told you that I don't think it was the alternator. Bad move
I took some reading on my car and they were almost the same as yours and I told you that I don't think it was the alternator. Bad move
#3
06-09-2010, 05:33 PM
Join Date: Oct 2004
Location: French - Montreal Canada
Posts: 551
Rep Power: 43 What is strange is WHY at startup is seems fine and then gets lower and lower (voltage) with the time...
#4
06-09-2010, 06:06 PM
if the alternator is putting out the voltage under load, the first thing I would do, without hesitation, is to quadrapule check each and every ground strap on the car.
If you are putting out 11.9-12.3 under a load, the car should start pretty much every time with a new battery just after you shut it down. Remember, with DC current, all those little electrons flow from negative to positive....
If you are putting out 11.9-12.3 under a load, the car should start pretty much every time with a new battery just after you shut it down. Remember, with DC current, all those little electrons flow from negative to positive....
#5
06-09-2010, 06:12 PM
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Join Date: Mar 2008
Location: Montreal Canada
Age: 69
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Rep Power: 266 Jp... I am crying ... I was telling myself... battery is new and everything else is ok... so can it be the alternator... So I took it off to be 100%%% sure... and it was not...
What is strange is WHY at startup is seems fine and then gets lower and lower (voltage) with the time...
What is strange is WHY at startup is seems fine and then gets lower and lower (voltage) with the time...
I reread again your first post https://www.6speedonline.com/forums/...ity-drive.html
and you seem to have a short of some kind (pinch wire ???). New battery, good alternator, still drop in voltage.... Remember the last big job on that car was the engine removal ???????
#6
06-09-2010, 06:24 PM
Join Date: Oct 2004
Location: French - Montreal Canada
Posts: 551
Rep Power: 43 I can feel your discouragement and I really feel sorry for you. That is why many of us, with our little experience and knowledge, are trying very hard to help people to fix and troubleshoot and especially to stay away from expensive repair.
I reread again your first post https://www.6speedonline.com/forums/...ity-drive.html
and you seem to have a short of some kind (pinch wire ???). New battery, good alternator, still drop in voltage.... Remember the last big job on that car was the engine removal ???????
I reread again your first post https://www.6speedonline.com/forums/...ity-drive.html
and you seem to have a short of some kind (pinch wire ???). New battery, good alternator, still drop in voltage.... Remember the last big job on that car was the engine removal ???????
#7
06-09-2010, 06:33 PM
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Join Date: Mar 2008
Location: Montreal Canada
Age: 69
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. Easier and cheapest things first!
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#9
06-10-2010, 06:13 AM
Join Date: Oct 2004
Location: French - Montreal Canada
Posts: 551
Rep Power: 43
Hi,
I don't think the belt is slipping as it is clear and looks new. No noise etc... Second, I took the alternator out and the guy who test it said it was like new, showing 13.8V no load and then 12.9V full load...
I don't think the belt is slipping as it is clear and looks new. No noise etc... Second, I took the alternator out and the guy who test it said it was like new, showing 13.8V no load and then 12.9V full load...
#10
06-10-2010, 07:11 AM
if the car's running at the time it's shut off, and doesnt start again and batts dead. I'm thinking something's draining the battery. similar to leaving a light on. thinking this drain has something to do with the alt. since it's generating low voltage, or perhaps the drain is pulling the voltage down. Don't know anything about electrics, so just shooting in the dark. hope you figure it out soon. this kind of stuff sucks.
#11
06-10-2010, 11:48 AM
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Location: Palos Verdes, California
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battery swap is relatively easy- why not just swap batteries, even though your battery is new, and then see?
#12
06-10-2010, 01:16 PM
you sure you reconnected the single blue wire in the back of the alternator when you put it back on the car? i've done that mistake before after putting on a new alternator and found was still not charging and it was the blue wire not snapped in all the way
#13
06-10-2010, 03:37 PM
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Look at the post from "logray". It is really interesting....http://www.renntech.org/forums/index...tt-alternator/
#14
06-10-2010, 03:41 PM
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Join Date: Mar 2008
Location: Montreal Canada
Age: 69
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Rep Power: 266 You want to see if the battery is at fault!!!! Only one cheap solution. Comes to my place and I will switch your battery with mine for a couple of days and we will see if it is the battery or if you got a short somewhere... Just PM me and I will give you my address and we can schedule a day for the swap... Of course free of charge....
#15
06-10-2010, 04:43 PM
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Location: Scotland
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Hi MZ3PO, I have the same problem as you and have a post out as well so I will be following your with interest. Try reading my post . 996tt Low voltage reading on Gauge .I am at the stage of removing my alternator, but I dont really want to unless I have some more info to work on. It could be something else. I do suspect a diode pack but we will see.
PM me if you wish and we can confer notes. This is really PI$$!NG me off to be honest after all the other problems I have had.
Touch base with me it might help us both.
Frank
anybody else want to share notes feel free.
PM me if you wish and we can confer notes. This is really PI$$!NG me off to be honest after all the other problems I have had.
Touch base with me it might help us both.
Frank
anybody else want to share notes feel free.