Diagnosis help please

ktraver97ss

I say what everyone thinks
Aug 29, 2007
13,458
142
Roselle, IL
So, I have a strange issue with my silverado.

First, some background info. It has a rewired HD alternator and 2 batteries to help with the elec load the plow puts on it. It has one Optima Red Top and the batt that was in the truck when I bought it over 5 years ago. I added the red top about 2 years ago wired in parallel. I learned that this is not right and I should have 2 of the same batt make/model and output to ensure no added strain on the alternator. Too late now. The alt was replaced at the same time as the red top was added. It has worked fine up until lately.

I noticed about a week ago that after a cold start the headlights would not reach their full brightness until I hit the gas pedal and got the alternator spinning faster. I didn't think much of it at the time, but it made me think about running larger power and ground wires off the alt. I havnt done anything to it yet and it acted up yesterday.

We were about to leave to go out for NYE, I start the truck and it barely starts and then dies. I figure I might not have cranked it enough or something so I do it again and it barley starts and begins idling at like 2-400rpm. not normal. I tap the gas and it revs up slowly and back to the low idle. I kill it and restart it and it does the same. I put in reverse and back up to see what is will do and it almost died when going back into drive. I decide to park it and take the Jeep.

So I think it could be the original batt sucking the life out of the system so I decide today to replace it with an other optima. I go to move the truck into the driveway to work on it and it starts up perfect. Idles normal, and the volts are pegged at 15-16 at idle in park. this is not normal as it is usually at 12v at idle. I dick with it, turn it on and off and drive it and now its completely normal. It did somehow reset the CEL, but not the radio memory.

Sorry for the narrative, but I wanted to include all the details. Should I just replace the batt like I was planning and then take it from there? Any ideas on what could have caused this for only that short period? It was much warmer yesterday, could that have affected it somehow? Gimme some ideas.
 

daturbosix

HNIC @ GoodFellas Garage
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Mar 2, 2008
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first, get rid of those junk ass optimas.

parallel wired batteries are the correct way to wire dual batteries unless you plan on running a 24v system.

what is your layout like? did you add another 4 ga. wire directly to the starter? or did you splice both hots together at some point and still use the single stock gauge power wire?
 

Yaj Yak

Gladys
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May 24, 2007
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why "junk ass optimas" ?

i have had my yellow top since 03 and it has never let me down at all- and my grand prix sits for 2-3 weeks at a time sometimes as of late, and always starts awesomely....

(which imo would be the correct battery for this application anyways due to the heavy electrical strain from the plow... redtops for starting- yellow for shit like this...)

they go to "junk" because no one knows how the fuck to charge them if they do get drained--- my buddy has a redtop that addvance and autozone said were junk, but when connected to a normal charger wired through another good optima- following the recharging shiznit that optima recommends- we were able to "bring it back to life"


imo- wire it correcttly- get the alternator rebuilt- and then throw it all back together and go for it.
 

daturbosix

HNIC @ GoodFellas Garage
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Mar 2, 2008
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ive had nothing but problems with optima batteries over the years, mainly because once they were dead, they were DEAD. i feel they are a WASTE of money, they dont provide anything "better" than a napa premium or orbital would offer, so why spend the extra change? a few years ago they were bought out by johnson control, which at this time they went to total shit, their warrenty was cut in half, and 9 time out of 10 your normal household battery charger will not bring them back.

ive brought some optimas directly to their distribution center in bensenville, and they were absolutly NO HELP with the situation.

i now buy the cheapest battery i can find, and ive never had a problem yet.
 

Yaj Yak

Gladys
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May 24, 2007
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howd you try to recharge em tho?

http://www.thechicagogarage.com/forum/showpost.php?p=577398&postcount=25

i just had a good talk with our interstate battery guy... and he told me to check out the stuff on the internet...

http://www.batteriesareus.com/index....522e22a1724cab

Quote:
Battery charging instructions:


* Voltage at the battery terminals when vehicle is running should Be from a minimum of 12.8 volts to < 15.0 volts
* Battery chargers should charge 13.8 ? 15.50 volts,

Never charge a battery at > than 15.6 volts.

We recommend the following charging procedure for a 34, 34/78, 75/35, and 6v:

1) Charge the battery A MINIMUM OF 100 amps for 15 mins ( @ 14.5+ volts)
a) Let battery and charger cool for 15 mins
2) Repeat step one at least four times - after letting battery cool 15 mins after each charge
3) Charge at 2-10 amps (trickle / automatic) for 24 hours minimum
4) Test the battery
5) D31 batteries: repeat each step again
--> WE ALWAYS RECOMMEND CHARGING TWO BATTERIES AT A TIME- CONNECT THEM POSTIVE POST TO POSITIVE POST ? negative post to negative post) AND PUT THE CHARGER NEGATIVE CABLE ON ONE BATTERY AND THE POSITIVE ON THE OTHER BATTERY! (and DOUBLE CHARGING TIMES)
ALL Optima's need Charged up if they have been discharged, before testing!




We compare charging an Optima to waking a teenager up on Saturday morning, or filling an empty 55-gallon drum with water ? it?s going to take some work!

Charging 10 amps on a drained 31 series battery is like filling a 55 gallon drum with an eye dropper!
Charging 10 amps on a drained 34/78 sries battery is like filling a 55 gallon drum with a 10oz cup - it can be done; but why?


Your alternator will not (and should not be used to) charge an OPTIMA up - unless you have a 100 amp alternator and less than 100 amp draw, and charge it for A long period of time with the car running. (and this will only ruin your alternator)


im betting the dudes in here who didnt have good luck with their optimas...

didnt charge em correctly... not that i would have known how before this... but its a pretty big deal...



mainly this part:

Quote:
> WE ALWAYS RECOMMEND CHARGING TWO BATTERIES AT A TIME- CONNECT THEM POSTIVE POST TO POSITIVE POST ? negative post to negative post) AND PUT THE CHARGER NEGATIVE CABLE ON ONE BATTERY AND THE POSITIVE ON THE OTHER BATTERY! (and DOUBLE CHARGING TIMES)
 

Bob Kazamakis

I’m the f-ing lizard king
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Oct 24, 2007
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My redtop optima lasted 5 years then wouldn't hold a charge. I could jump it and it would last all day with starts and stops. Then park it overnight an it wouldn't start again. I bought the cheapest battery I could find at farm & fleet. Cost like $65 and has the same warranty as my optima did. Fuck $150 batteries.....
 
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