Now Voltage Fluctuating?
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
These readings are coming from the DIC, then I took the volt meter and measured the pos alt, it was reading the same thing irratic, the batt stays at 12
During initial start up (cold start )the DIC reads 14.1 volts, until it warms up then it become irratic back to 11.7 then 12.5 etc etc.
I just took the alt to get tested at autozone and oreilly's and it passed.
During initial start up (cold start )the DIC reads 14.1 volts, until it warms up then it become irratic back to 11.7 then 12.5 etc etc.
I just took the alt to get tested at autozone and oreilly's and it passed.
A fully charged battery should be 12.6v or more.
If the battery is
12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained
Any difference in readings between directly at the battery and what the DIC says, is probably the ignition switch.
Difference in readings between directly at the alternator and directly at the battery, is probably something along the way in the "alternator-starter-battery" links.
This is the reason I've been asking you for accurate readings at those 3 places (DIC, battery and alternator), so we can compare them and draw conclusions. Can you do a table like this? (just an example):
DIC: 13.1
Battery: 13.9
Alternator: 14.1
And do it at least 3 times, let's say when engine is cold, warm and hot?
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
If your battery only measures 12v (with a multimeter directly at the battery posts) it should be completely discharged.
A fully charged battery should be 12.6v or more.
If the battery is
12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained
Any difference in readings between directly at the battery and what the DIC says, is probably the ignition switch.
Difference in readings between directly at the alternator and directly at the battery, is probably something along the way in the "alternator-starter-battery" links.
This is the reason I've been asking you for accurate readings at those 3 places (DIC, battery and alternator), so we can compare them and draw conclusions. Can you do a table like this? (just an example):
DIC: 13.1
Battery: 13.9
Alternator: 14.1
And do it at least 3 times, let's say when engine is cold, warm and hot?
A fully charged battery should be 12.6v or more.
If the battery is
12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained
Any difference in readings between directly at the battery and what the DIC says, is probably the ignition switch.
Difference in readings between directly at the alternator and directly at the battery, is probably something along the way in the "alternator-starter-battery" links.
This is the reason I've been asking you for accurate readings at those 3 places (DIC, battery and alternator), so we can compare them and draw conclusions. Can you do a table like this? (just an example):
DIC: 13.1
Battery: 13.9
Alternator: 14.1
And do it at least 3 times, let's say when engine is cold, warm and hot?
Yes Thank You for your response and patience with my situation. I am at work now, but here is what I have so far:
DIC: 14.1 initial start up, then fluctuates as explained above when car is warmed up
Battery: Ranges from 12.2-12.5 at the Terminals
Alternator: Yesterday was reading 12.9, 13.5 14.1
Hope this helps.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
So I guess my question would be, would a bad fuse or short cause the voltages to fluctuate during warm up. DIC dropped as low as 11.7.
I cleaned all the grounds on frame and tighned them up, some were dirty. Car starts up without hesitation.
I cleaned all the grounds on frame and tighned them up, some were dirty. Car starts up without hesitation.
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
I was trying to establish if the voltage fluctuations are "in sync" in all 3 devices (alternator, battery and DIC). In other words, whether or not all 3 readings are simultaneously affected in the same way and by the same amount.
If the alternator-starter-battery-ignition switch-DIC links are fine, the fluctuations should be in sync and readings in all 3 points should be very close in value. Have you checked if you have a significant drop of voltage between the alternator and the battery? Using your multimeter measure the voltage between the alternator and the positive post of your battery. Ideally it should be zero, but close enough is fine.
If all this checks, and considering you already tested your alternator, it could be your alternator's clutch/decoupler is acting up.
If the alternator-starter-battery-ignition switch-DIC links are fine, the fluctuations should be in sync and readings in all 3 points should be very close in value. Have you checked if you have a significant drop of voltage between the alternator and the battery? Using your multimeter measure the voltage between the alternator and the positive post of your battery. Ideally it should be zero, but close enough is fine.
If all this checks, and considering you already tested your alternator, it could be your alternator's clutch/decoupler is acting up.
Race Director
Joined: May 2003
Posts: 14,137
Likes: 2,984
From: Iowa
St. Jude Donor '03 thru '26
If your battery only measures 12v (with a multimeter directly at the battery posts) it should be completely discharged.
A fully charged battery should be 12.6v or more.
If the battery is
12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained
Any difference in readings between directly at the battery and what the DIC says, is probably the ignition switch.
Difference in readings between directly at the alternator and directly at the battery, is probably something along the way in the "alternator-starter-battery" links.
This is the reason I've been asking you for accurate readings at those 3 places (DIC, battery and alternator), so we can compare them and draw conclusions. Can you do a table like this? (just an example):
DIC: 13.1
Battery: 13.9
Alternator: 14.1
And do it at least 3 times, let's say when engine is cold, warm and hot?
A fully charged battery should be 12.6v or more.
If the battery is
12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained
Any difference in readings between directly at the battery and what the DIC says, is probably the ignition switch.
Difference in readings between directly at the alternator and directly at the battery, is probably something along the way in the "alternator-starter-battery" links.
This is the reason I've been asking you for accurate readings at those 3 places (DIC, battery and alternator), so we can compare them and draw conclusions. Can you do a table like this? (just an example):
DIC: 13.1
Battery: 13.9
Alternator: 14.1
And do it at least 3 times, let's say when engine is cold, warm and hot?
12V would be about 44% charged, not completely discharged. 
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
UPDATE:
Well I reexamined the battery well on passenger side and a couple of ground locations caught my eye. The ground next to the battery was turned inside close to battery so I loosened it and turned it vertical away from battery, also moved away the cables from being crimped up on bottom both neg and pos, also unloosened the pos to the fuse box, apparently they were mixed up the ground some how was touching the smaller wire so I seperated them rearranged then not to touch each other and now the information on the DIC is much more stable now, still showing lower but more stable. Had a good 14.2 charge during initial start up and went all the way down to 11.7, but I think that is off alil maybe .3 so should be reading 12v.
Don't know if the New Starter has new electronics in it for it to get such a low charge but the car starts right up, no hesitation, no codes. The only codes I have was the Charge System Fault, but that was from running jumper cables on the battery to try and restart battery when old starter was on it. So I am finished with this dilemma. Everything works fine. Just still showing a lil low, but I think that could possible be the electronics in the new starter.
Well I reexamined the battery well on passenger side and a couple of ground locations caught my eye. The ground next to the battery was turned inside close to battery so I loosened it and turned it vertical away from battery, also moved away the cables from being crimped up on bottom both neg and pos, also unloosened the pos to the fuse box, apparently they were mixed up the ground some how was touching the smaller wire so I seperated them rearranged then not to touch each other and now the information on the DIC is much more stable now, still showing lower but more stable. Had a good 14.2 charge during initial start up and went all the way down to 11.7, but I think that is off alil maybe .3 so should be reading 12v.
Don't know if the New Starter has new electronics in it for it to get such a low charge but the car starts right up, no hesitation, no codes. The only codes I have was the Charge System Fault, but that was from running jumper cables on the battery to try and restart battery when old starter was on it. So I am finished with this dilemma. Everything works fine. Just still showing a lil low, but I think that could possible be the electronics in the new starter.
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Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
Problem Fixed:
For those experiencing with this it was the smaller electrical connection on the post on starter. It was barley connected on the copper connection because it was burned. Had to re splice the elect line. Now volts reading 13.5 stable.
For those experiencing with this it was the smaller electrical connection on the post on starter. It was barley connected on the copper connection because it was burned. Had to re splice the elect line. Now volts reading 13.5 stable.
Glad you figured it out.