Well today I bought a Duralast Gold 105 amp alternator. I installed it and I was so excited to watch my voltage be fixed......but of course the problem is still there. My buddy suggested something interesting though. There's a grayish wire that is hooked to a connector & screwed on the back of the alternator. He suggested that this wire may be bad or too small. What exactly is this wire? And where is the other end going to? Thanks!

 

what is the problem?

 

THE WIRE THAT is bolted on to the back of your alt goes to your battery.. usually uses 8 guage wire i would think at least mine does.. my wire is brittle so i am changing mine.. i think we have the same problem.. i dont have underdrive pulleys and my problem isnt just at idle though.. my car just isnt charging...
ShAWN

 

hey put a fuse in the fan spot on your fuse panel..

 

I have one there...Why do you say that?

 

Pull the plug at the top of the alt, it should have 2 wires. With a voltmeter and key on engine off measure the voltage at both wires. One should read what the battery is, the other lighter guage wire should be a half of a volt or so lower. Also, with the key off measure the voltage from the lug on the rear of the alt to ground. It should also be at battery voltage. If all 3 things are OK, you have a bad alt or your guage is not reading properly. With the engine running measure across the battery terminals with the meter. You should have approx 13.5 14.5 volts average at idle with the accessories off. He mentions the fuse because the sense wire for the alt gets voltage through that fuse. If it is bad the sense wire stays low causing the alt to put out very little if any output.

 

i say that because thats where the black wire goes... i would change bak to a 2c wire connecter if you still have yours..check the fan fuse with car on.. if it doesnt get any power you found you problem.. the voltage regulater uses that one spot to find voltage drops and charge the car... my car runs at 15 all day now...

who would've known... although if you do a electrical search danno pops up everywhere....

hit me up on aim with questions...
Shawn

 

Dat's cause it's the only thing I'm good at.

 

ok.....I went out there for a couple hours and did some tests. Keep in mind this is my first time using a volt meter lol. Well I put it on DC-V 50. With the car completely off and no key in the ignition....here's what I got.

Red wire going to plug : +10 dB
Brown wire going to plug : NO READING AT ALL :-/ hmm
Back lug on Alt. : +10 dB
Positive Battery Terminal : +10 dB
Negative Battery Terminal : NO READING
Fan fuse : NO READING


ok here's with the ignition on but car off

Red wire going to plug : +10 dB
Brown wire going to plug : NO READING AT ALL
Back lug on Alt. : +10 dB
Positive Battery Terminal : +10 dB
Negative Battery Terminal : NO READING
Fan fuse : +10 dB BUT when I disconnected the brown wire I got no reading at all.

Car on = Same

Also...When I began testing with the voltmeter...When I put the positive on the red wire, it sparked and charred the wire a little bit....
I re-spliced all the connections and made sure they were all connected strong.....and now for some reason my voltage guage reads about 10-11 constantly. Before it jumped around when I gave the car gas....now it just stays there.

Any ideas would be GREATLY appreciated. Thanks!!!

 

Well on my way home from work.....I saw the voltage slowly and slowly getting lower until my lights were almost completely dark. It was super scary. Then when I turned my car off it wouldn't start up again. Surprisingly, my idle was back to normal - 7 or 8. after i installed my new alternator they dropped down to 6. So I took out my fan fuse and it was blown. I put a new one in and it started fine....my idle was back to low...and my voltage was back to low and going up when i rev. :[

 

okay Danno,

I took my battery out and charged it with a battery charger over night. No difference. I have no idea what else to try!!!!!!!!!!!!!!!!!!!! AHHHHHHHHHHHHHHHHHHHHH

 

I am also having this issue currently. I replace my alternators on almost a weekly basis.

I eventually got tired of the fan issues and just put it on a toggle. Of course that is not a perfect solution either because the alternator seems to hate when I turn it on. If anyone finds the solution to this issue, please post it.

I am thinking of taking mine to an electric shop.

 

If you replace the alt that often something else is going on. First, and if you have read any of my posts I strongly urge NOT to fool with fan on and offf temps and leave it stock assuming everything else in the cooling system works. Both the Si and CS Delco alternators have all important components internal to the alt and need only 2 or 3 things depending on model to work. The wire from the back to the battery, 12 volts to red wire at plug and if applicable the sense wire which also has 12 volts(actually a little less) to control charging and monitor electrical demand. A brand new 105 amp unit on a TG with both fans running, headlights on and A/C with blower motor on high and compressor clutch engaged will NOT have sufficient output at hot idle for everything. There are times when you run off the battery in these conditions. As soon a you come slightly off idle it should run right back up to at least 13-14 volts and recharge the battery. Before you take it to the shop what exactly are you experiencing? I stopped messing with cars after I sold my 67 Chevelle, but I got tired of having to spend money at the dealer especially when I got the IROC only to get it back as bad if not worse. E.G., just out of warranty int MAF code-700 bucks later same thing. Got some training manuals on the newer stuff and $14 later replaced the burnoff relay. With 4 GM cars driven by 3 females I would be living in a tent if I had to pay dealer prices especially if the repair was hit and miss.

 

Thank you for all your help, Danno. Alright, here is what I'm experiencing.....

I just went out, sat in my car and recorded this:

RADIO OFF - BLOWER OFF


Car cold in park - Everything off = Voltage - 15 RPM - 15

^^^^Same but after 5 minutes = Voltage - 14.5 RPM - 7

Car Semi-warm in drive but not moving - Voltage jumps to 13, almost stalls, then goes back upto 14 - RPM - 6

Car warm in park - when turn fans on Volt. drops to 13, then wobbles between 13-14 occasionally

Car warm - in drive - fans on - Volt = 12.5 Idle - 5.5



I've cleaned all the connections I can find. I've replaced the Alternator Pigtail...All they had is a 3 wire so I'm using that, but it made no voltage difference over my original 2 wire. I have the red on the pigtail going to the red and the Black on the pigtail going to the brown wire. The brown pigtail wire isn't connected to anything. I've had the battery checked on numerous occasions......All coming back Good Charge....I charged it overnight yesterday with a Battery Charger....No difference. I replaced my old alternator to a 105 amp Duralast Gold. When I did this, my voltage increased a TINY bit...but my Idle dropped from 7-8 to about 6. I even bought battery ground cable and grounded the whole engine. I've checked all the fuses. Although.....When my fan fuse blew a couple weeks ago.....my RPM's at idle went back to normal 7-8. But after replacing it, it went back to 6. I do have a 400w amp with a 12" JBL.........But this voltage problem was there way before this. That just makes it worse. When I stop at a stoplight....My voltage drops & my lights dim and when I start going again, it rises to normal 13-14 and my lights get brighter. The voltage guage wobbles with the turn signals....When I'm driving at night...And I turn on the fans....My lights get real dim and when the bass hits....people think I'm flashing them :\ lol. My belt looks very new...and is pretty tight. I don't believe I have underdrive pulleys. I'm really out of ideas. But if anyone has any....That'd be great. Thanks everybody.

 

[QUOTE]Originally posted by CamaroRS91x
[B]Thank you for all your help, Danno. Alright, here is what I'm experiencing.....

I just went out, sat in my car and recorded this:

RADIO OFF - BLOWER OFF


Car cold in park - Everything off = Voltage - 15 RPM - 15

^^^^Same but after 5 minutes = Voltage - 14.5 RPM - 7

Car Semi-warm in drive but not moving - Voltage jumps to 13, almost stalls, then goes back upto 14 - RPM - 6

Car warm in park - when turn fans on Volt. drops to 13, then wobbles between 13-14 occasionally

Car warm - in drive - fans on - Volt = 12.5 Idle - 5.5



Dude, you are really OK. Look at the guage, the engineers gave you a white normal zone and the red problem area. What does it say. The range you state is NORMAL. If it ain't broke, don't fix it. Your charging system is operating correctly. Don't overlook the fact that the alt as it gets hot throttles back to protect the rectifier package and the reg IC. Most of the TG's I see drop down to close to 9-10 volts with the fans on and headlights and A/C.