Loose battery cable
Burning Brakes
Joined: Mar 2012
Posts: 769
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From: California
FL Events Coordinator
St. Jude Donor'13
I was pulling around 4 amps! Hunted down the fuses and it was the CTSY/CLK. Left fuse out and ran car. With engine hot, it was charging at high 13's to 14's and dropped into low to mid 12's with all lights on and turn signals while in gear with brake on. No more erratic volt readings as before steady readings and they only changed with introduction of more amperage or reduction of. Car charges at steady 14.1 with rpms at about 1800-2000. I let it run for a good 10-15 minutes and parked it. Checked battery and it charged up to 12.8. Going to check again in morning to see if it is holding. The lower than normal volt reading although better than what it was doing, I attribute to the under drive pulley on the alternator. I am going to find a stock one to put on if the current changes do not keep the battery charged properly. I think the old Kenwood stereo I had in my garage that I installed in the car when I bought it in May could be the culprit. More experimenting to come. I need to get my heat and AC back online! They are apparently on that circuit.
Thread Starter
Racer
Joined: Feb 2012
Posts: 442
Likes: 3
From: Hendersonville TN
I was just looking at wiring diagrams for that circuit and I saw there is a pink wire for the stereo that goes to the power antenna. My power antenna is not in use. The previous own had a small powered antenna installed that sticks to the windshield behind rear new mirror when the power antenna motor went out. I wonder if I wired up the pink power antenna wire when installing the Kenwood stereo and it is constantly trying to activate the antenna motor? Gonna pull stereo out tomorrow and search.
Safety Car
Joined: Aug 2002
Posts: 3,842
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From: SANTA CRUZ CA
Originally Posted by HandsomeMike
I.......Gonna pull stereo out tomorrow and search.
Sounds like you are progressing nicely...... good luck.
Thread Starter
Racer
Joined: Feb 2012
Posts: 442
Likes: 3
From: Hendersonville TN
Seabright- good idea. I will make notes on the wiring diagram for each wire so I know what they are really doing. Do you guys think putting a stock size pulley back on the alternator would be a wise idea regardless?
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
Originally Posted by HandsomeMike
...... Do you guys think putting a stock size pulley back on the alternator would be a wise idea regardless?
Last edited by don hall; Dec 22, 2013 at 08:21 PM.
Burning Brakes
Joined: Mar 2012
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From: California
FL Events Coordinator
St. Jude Donor'13
I doubt your undersized pulley really does much anyway. Something like that should most likely be stock anyway. It should give you better charging for sure.
Also take pictures and make wiring diagrams. Anything electrical I do to my car I make a really good wiring diagram for so that if I ever sell it or need to do something I know what is what.
Thread Starter
Racer
Joined: Feb 2012
Posts: 442
Likes: 3
From: Hendersonville TN
Soooo... I'm an idiot. The 3.5 amp draw was from the interior lights. Even with the negative cable removed and both doors closed and under hood lights unplugged, when you put one DVM lead on the cable and the other on the post and create the connection, the interior lights will come on for 45 seconds as if you had opened and closed the doors normally. That was my draw. I held the leads on till the lights cycled off and there is no draw. Moral of the story is, under drive pulleys don't charge worth a s**t and kill your battery faster! All is fine with the world and I just need to get a stock size alt pulley. At least I have now disassembled half of my car and put it back together and learned a lot about where different plugs and relays are! I love my car. I love my car. ;-)
Former Vendor
Joined: Nov 2009
Posts: 279
Likes: 20
From: Glendale Wisconsin
Mike, 12.7 volts with the car turned off after just being driven could be a surface charge, that might dissipate after sitting for several hours. A more accurate voltage reading would come after the car has been sitting for several hours or overnight. Disconnecting the battery from your car while it sits will eliminate any parasitic draw from the equation. Measuring voltage directly at the terminals is the most-accurate way to measure, versus dash-mounted gauges (I have seen as much a 1.0 volt-drop betweeen the battery and the gauge). Many drag racers run cars without any charging system and simply charge the battery in between rounds. It's not ideal for a street car, but it's better than the alternative and a scenario better-suited for a YellowTop than a RedTop. Batteries can be recovered from deep-discharges, but the deeper the discharge, the more life is taken from the battery. Our YellowTops are designed (and warrantied) for deep-cycle use, while RedTops are designed for starting only.
xrav22, your battery voltage sounds low. Are you measuring that at the terminals or off a dash-mounted gauge?
Jim McIlvaine
eCare Manager, OPTIMA Batteries
www.pinterest.com/optimabatteries
xrav22, your battery voltage sounds low. Are you measuring that at the terminals or off a dash-mounted gauge?
Jim McIlvaine
eCare Manager, OPTIMA Batteries
www.pinterest.com/optimabatteries
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Burning Brakes
Joined: Mar 2012
Posts: 769
Likes: 22
From: California
FL Events Coordinator
St. Jude Donor'13
Soooo... I'm an idiot. The 3.5 amp draw was from the interior lights. Even with the negative cable removed and both doors closed and under hood lights unplugged, when you put one DVM lead on the cable and the other on the post and create the connection, the interior lights will come on for 45 seconds as if you had opened and closed the doors normally. That was my draw. I held the leads on till the lights cycled off and there is no draw. Moral of the story is, under drive pulleys don't charge worth a s**t and kill your battery faster! All is fine with the world and I just need to get a stock size alt pulley. At least I have now disassembled half of my car and put it back together and learned a lot about where different plugs and relays are! I love my car. I love my car. ;-)
Did you do the parasitic draw test on the negative cable or on the positive? It is better to do it on the negative side so you don't accidentally ground your positive cable which would be bad.
Burning Brakes
Joined: Mar 2012
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From: California
FL Events Coordinator
St. Jude Donor'13
My battery is bad but it still works the same either way, but the dash mounted gauge for my 89' corvette will read like 11.2V after sitting overnight but when I put my multi-meter on it, it will read 11.5v plus or minus .2V.
The dash gauge is not very accurate when the car is just sitting in the on position not running. However, when mine is running and charging the reading on the dash is much more accurate but still not 100% accurate.
Also, yes I know my battery is very bad. I am going to get one within the next few days.
The dash gauge is not very accurate when the car is just sitting in the on position not running. However, when mine is running and charging the reading on the dash is much more accurate but still not 100% accurate.
Also, yes I know my battery is very bad. I am going to get one within the next few days.
Thread Starter
Racer
Joined: Feb 2012
Posts: 442
Likes: 3
From: Hendersonville TN
Optima- I checked it this morning with negative cable off at the posts with DVM and it was 12.5. Loss of .2 overnight.
RedL98- I used the negative cable for parasitic loss test as I read it was the safer side to use. I looked back through the big binder of car records this afternoon and saw that the only pulley changed was the crank pulley back in 1998. It was bought from Mid America but the part numbers from then aren't the same anymore. The next receipt shows the bill for the install from a Vette shop in TX with a labor description saying installed lower pulley. It doesn't say anything about the alt pulley being replaced and be only paid about $80 for the pulley. A two or three piece set would have been around $150+. Even just the under drive crank pulley will slow down the alt I believe. There are other receipts showing the charging system was charging at 11.7 in drive with accessories on and the mechanic doing the service gave it an "ok" diagnosis. Alt has been replaced at least twice from the records I have. I may just get a battery tender to keep on it being as I only drive it about once a week.
RedL98- I used the negative cable for parasitic loss test as I read it was the safer side to use. I looked back through the big binder of car records this afternoon and saw that the only pulley changed was the crank pulley back in 1998. It was bought from Mid America but the part numbers from then aren't the same anymore. The next receipt shows the bill for the install from a Vette shop in TX with a labor description saying installed lower pulley. It doesn't say anything about the alt pulley being replaced and be only paid about $80 for the pulley. A two or three piece set would have been around $150+. Even just the under drive crank pulley will slow down the alt I believe. There are other receipts showing the charging system was charging at 11.7 in drive with accessories on and the mechanic doing the service gave it an "ok" diagnosis. Alt has been replaced at least twice from the records I have. I may just get a battery tender to keep on it being as I only drive it about once a week.
Burning Brakes
Joined: Mar 2012
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From: California
FL Events Coordinator
St. Jude Donor'13
If my memory serves me correctly, the 12.5v after overnight is just fine, like optima said the 12.7v right after words is good for just after it is shut off. But that is a surface charge and will drop to 12.5v shortly after which is a good spot to be at.
I just checked 2 of the other cars at my house and they are both at 12.4v and 12.3v after 2-3 days without use.
So that should be normal.
11.7v in drive with all accessories is not good at all mine with a weak battery with all accessories will charge at 12.7v-12.8v at idle and 13.5v-13.7v while driving.
Since you only drive it once a weak I think it is a good idea to put a battery tender on, it will help with battery life and they are good priced.
I definitely recommend changing that crank pulley back to the original.
Good Luck
I just checked 2 of the other cars at my house and they are both at 12.4v and 12.3v after 2-3 days without use.
So that should be normal.
11.7v in drive with all accessories is not good at all mine with a weak battery with all accessories will charge at 12.7v-12.8v at idle and 13.5v-13.7v while driving.
Since you only drive it once a weak I think it is a good idea to put a battery tender on, it will help with battery life and they are good priced.
I definitely recommend changing that crank pulley back to the original.
Good Luck
Thread Starter
Racer
Joined: Feb 2012
Posts: 442
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From: Hendersonville TN
But I need that extra 2hp! ;-). 11.7 was the reporter charge back in the day from a previous owners service records. I have a 3 ring binder of just about every purchase, service, emissions test, etc. since 1993. The car right now is charging in the low 12's at idle in drive with lights and AC on. Goes up to high 13's to 14 when driving. I may just do the battery tender. Even if I switch back to a stock crank pulley I could still use one being as I don't drive it every day. Thanks to all for your input. This is why I love this forum! Merry Christmas to you guys just in case this thread is done.
Burning Brakes
Joined: Mar 2012
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From: California
FL Events Coordinator
St. Jude Donor'13
But I need that extra 2hp! ;-). 11.7 was the reporter charge back in the day from a previous owners service records. I have a 3 ring binder of just about every purchase, service, emissions test, etc. since 1993. The car right now is charging in the low 12's at idle in drive with lights and AC on. Goes up to high 13's to 14 when driving. I may just do the battery tender. Even if I switch back to a stock crank pulley I could still use one being as I don't drive it every day. Thanks to all for your input. This is why I love this forum! Merry Christmas to you guys just in case this thread is done.
With everything on at idle and your at least charging in the 12v range then you are good. And since you only drive it once a week the stock crank is not a 'must', but it is still probably recommended. I mean since when driving you still charge excellent I would actually leave it alone. Maybe change the crank when you have nothing to do one day or if you get bored.Have a good Holiday and thanks to you also for helping me choose which battery I will get
Thread Starter
Racer
Joined: Feb 2012
Posts: 442
Likes: 3
From: Hendersonville TN
Update: two days later the battery has only dropped from 12.5 to 12.45.
Battery is good. Under drive pulleys are bad!!! :-)
Merry Christmas to all and to all I will probably be posting again soon in a new thread when my VBP front 32mm sway bar arrives!!!
Battery is good. Under drive pulleys are bad!!! :-)
Merry Christmas to all and to all I will probably be posting again soon in a new thread when my VBP front 32mm sway bar arrives!!!
Burning Brakes
Joined: Mar 2012
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From: California
FL Events Coordinator
St. Jude Donor'13
Can't wait to see the install guide that you ARE going to make for the new sway bars
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Racer
Joined: Feb 2012
Posts: 442
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From: Hendersonville TN
It'll be close to March before I do it being as I hate cold weather and the garage does not stay very warm, but yes, I will do a fully documented with pictures write up on the front and rear install.
Burning Brakes
Joined: Mar 2012
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From: California
FL Events Coordinator
St. Jude Donor'13
The one good thing about florida haha it is hot almost all the time even when it gets cold it hardly ever goes below maybe 40 degrees and when it does get that cold it is only for a day or two. The downside is it rains a lot.
