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rleng1
12-20-2011, 05:52 PM
Battery reads 17v prior to startup. 16.4v while running(voltmeter). 10v on the cluster gauge. Normally would read 13.5v. Car runs fine and idles smooth.

Ideas/suggestions????

Wade
12-20-2011, 09:17 PM
Buy a FORD! Hahaha

rleng1
12-20-2011, 09:35 PM
I knew it was coming. I would but they aren't selling season passes.

David Love AI27
12-21-2011, 01:42 AM
Battery reads 17v prior to startup. 16.4v while running(voltmeter). 10v on the cluster gauge. Normally would read 13.5v. Car runs fine and idles smooth.

Ideas/suggestions????

17 Volts?... wow... sure that is not 12?... Lately I found it easier to read a volt meter with my new reading glasses...

nasa-rm
12-21-2011, 12:38 PM
I'd say borrow a meter to cross check.

Fbody383
12-21-2011, 01:04 PM
I'd say borrow a meter to cross check. Or, just add some ballast. Being light means the electrons don't have as much work to do through the ground so the voltage runs a little high.

David Love AI27
12-21-2011, 04:41 PM
Or, just add some ballast. Being light means the electrons don't have as much work to do through the ground so the voltage runs a little high.

Don't listen to Dave... he's a little light himself... light in the head...

rleng1
12-21-2011, 05:00 PM
why did i bother????

Casey_SS
12-21-2011, 06:09 PM
Randy - I would guess you have a bad voltage regulator on the alternator and maybe a bad cell in the battery to boot. I'd take both down to your local Autozone and have them tested before spending any money though.

If you still have most of the factory wiring harness and ignition key, turning the key to "on" with the motor off will display battery voltage on the stock gauge. Once you start the motor, it shows alternator output. If your battery is truly overcharged, this would explain the low 10v reading with the motor running - alternator output would drop while the system tries to stabilize itself.

GlennCMC70
12-21-2011, 07:03 PM
Things to keep in mind.
A "12 volt battery" will never have more than 2.24v per cell. A car battery is a 6 cell battery. It can never put out more than 13.44 volts total. Once the car is running the alt will change that reading (system voltage) to whatever the alt is putting out. I don't think a good alt will put out more than 16 volts. If it does (as Casey said) the regulator is bad. So w/ the car off and the battery is putting out alot less than 13.4 volts (10 is alot less), this points to a shorted cell. W/ one cell not putting out it's share of 2.24v per cell (5 cells now) you will at best see 11.2 volts. Using 2 volts per cell for a battery that has been sitting (normal) you get the 10v you see now.

David Love AI27
12-21-2011, 07:46 PM
I'd say borrow a meter to cross check.

I got one... no plans for the holidays.. I can stop by anytime

rleng1
12-21-2011, 09:34 PM
Using my volt meter on my truck, I read 17v as well. I will cross check my meter, then begin the other possible issues. Thanks for the advise.

cobra132
12-21-2011, 09:55 PM
A fully charged battery should only read 13.6v. With car off if you are reading 17 then something is wrong with meter or battery. Should get 14 to 15 at battery with a normal charging system when running. But after seeing the end of year video, anything is possible. FMR

David Love AI27
12-22-2011, 08:54 AM
Using my volt meter on my truck, I read 17v as well. I will cross check my meter, then begin the other possible issues. Thanks for the advise.

Like I said.. I can come over with my meter... 281-414-1738

rleng1
12-22-2011, 11:20 AM
have a hunch, its my alternator.
suggestions for brand and amperage on alternator?

Casey_SS
12-22-2011, 12:01 PM
have a hunch, its my alternator.
suggestions for brand and amperage on alternator?

I've seen no difference in reliability between Autozone or O-Reilly's alternators. In AIX trim (~6400rpm shift point), both would last slightly longer than a set of brake pads. I've been through several of each and finally settled on Autozone as they're marginally closer to most tracks we race at. I now carry a spare and save the warranty dance for when I'm not in a rush. Last year I tried an experiment and ordered a 4" pulley from Canton Racing to replace the stock 2.5" pulley and slow the alternator down. Haven't had a failure since (knock on wood). In AI trim, it's counterproductive to rev past 5700 rpm - I expect this to also have a positive effect.

If you like tinkering, you can order the parts you need pretty cheap from here and rebuild it yourself - http://www.aspwholesale.com/. I would think the stock amperage rating should be more than sufficient for a race car...

AllZWay
12-22-2011, 12:34 PM
I had a local alternator repair shop beef up the parts in the one in my car now. I also got tired of replacing them at least once a year. Since they put good parts in it, it has been for almost 2 years.

rleng1
12-22-2011, 02:34 PM
got new voltmeter. Battery reads 12.6v without the car running. 11.4 with the car running. Seems like an alternator to me. Voltage gauge reads 10.5v.
Up goes the car and out comes the alternator. Easy way of dropping the alternator out. Remove sway bar???
Thanks for all the advice.....from most of you.

BryanL
12-22-2011, 02:40 PM
I went through some alternator issues as well when I had a battery going bad and a small charge wire coming off the alternator. I just checked ebay and a AC Delco reman is sky high. During my fiasco I found a brand new alternator I think from Katech for around $100 on ebay-glad I still have that hidden somewhere.

HoustonNW
12-22-2011, 04:49 PM
I removed the sway bar the last time I replaced mine and it made a huge difference - much, much easier.

Edit to add: Make sure the power cable that attaches to the alternator is clean and not corroded. That is what was killing my alternators.

David Love AI27
12-22-2011, 10:23 PM
got new voltmeter. Battery reads 12.6v without the car running. 11.4 with the car running. Seems like an alternator to me. Voltage gauge reads 10.5v.
Up goes the car and out comes the alternator. Easy way of dropping the alternator out. Remove sway bar???
Thanks for all the advice.....from most of you.

Did you rev the motor and check the output?? I had the same issue with mine at idle in the 27 car but if I got the revs up to 1,000-1,200 it kicked up to nearly 14 volts... I do have and underdrive crank pully.. caused power steering issues also at low rpm..

BryanL
12-23-2011, 10:21 AM
got new voltmeter. Battery reads 12.6v without the car running. 11.4 with the car running. Seems like an alternator to me. Voltage gauge reads 10.5v.
Up goes the car and out comes the alternator. Easy way of dropping the alternator out. Remove sway bar???
Thanks for all the advice.....from most of you.

I never pulled the swaybar to change them. Just snaked it out-getting it back in was a little more difficult but easy with 4 fingers.

rleng1
01-13-2012, 07:31 PM
Pulled the alternator, tested good. Any ideas? Will re-install alternator using all 5 fingers. Could it possibly bye a ground problem somewhere. Anything else to chase? Thanks.

Casey_SS
01-14-2012, 12:07 AM
Try swapping batteries with your truck and see if anything changes. You could also take both ohm and voltage readings across the master disconnect to see if anything weird is going on there...seems to happen from time to time. Other than that, double check all your chassis grounds...not sure how many you have or where they are on an LS1 though, sorry.

BryanL
01-14-2012, 09:53 AM
What gauge is your charging wire that goes back to the backside of the master disconnect

rleng1
01-14-2012, 11:18 AM
6ga wire. Thanks for the ideas. Will check voltage from alternator back to battery while car is running.

rleng1
01-14-2012, 03:28 PM
Installed alternator. Fired up car. Everything normal. 14.4v at the battery while running.
MSRH here we come.

Casey_SS
01-15-2012, 02:15 AM
Good news Randy....glad to hear it. Sounds like the car just felt neglected and wanted some attention. They don't like to go too long without hearing some obscenities. ;)

Fbody383
01-17-2012, 09:39 AM
They don't like to go too long without hearing some obscenities. ;) I got mine a yoga mat to keep her happy. Mighty LS1 power coming to H-town...

mitchntx
01-17-2012, 10:43 AM
Pulled the alternator, tested good. Any ideas? Will re-install alternator using all 5 fingers. Could it possibly bye a ground problem somewhere. Anything else to chase? Thanks.

I will assume the alternator was tested by the pimple-faced kid at a chain auto parts store, using a generic spin tester and an over-used, severly abused adaptor pig-tail.

I say this because I've had good alternators test bad, bad alternators test good, new alternators test bad, but be good and new alternators test good and still be bad and on the rare occasion ... a good one tests good and a bad one actually tests bad..

If removing it and just putting it back in "fixed" the problem, I would look at connections, crimps and solder joints. Most likely, it won't stay "fixed".
It's been my experience that very little fixes itself.

rleng1
01-17-2012, 02:03 PM
Excellent diagonsis Mitch. I'm sure it is the same electrical gremlin I had at Hallet, where we removed and re-installed the starter, and it worked fine. Once before I removed and replaced the fuse box at Cresson. It seems that there is a force field around my car, and it locks up. Once I break the field, it re-establishes itself, and the re-energies itself.
maybe I need to stick one of those nuclear rods up the tailpipe.