Alternator

Hey folks. I noticed tonight on the way home that my turn signal seemed to blink a little slower than normal and figured I might have a light out. Then noticed a bit later that my voltage was showing 11.5 running at 70mph. Haven't had the alternator tested yet but if it is bad that will be the third one in a years time. The first time it went about a year ago, the connector broke with me so I bought a new one from GM. The new pig tail had two white wires and the old one had color coded. The wires look the same in size so I wonder if I have the pig tail hooked up backwards or is that possible. The last alternator seemed to over charge a bit usually running around 14.5. Was that too high or about right. I know 11.5 is too low.

What should I check for to see why I'm eating alternators or have I had a run of bad luck the poor quality ones?!!

Thanks in advance for input.

Chris

[jester]

Are you putting in AC Delco or auto parts store rebuilds? The first one I replaced was with a parts store rebuild. It lasted a little over a year. Then a parts guy explained the difference in the alternators. I put out the extra bucks for the AC Delco and haven't had another problem in over 3 years.

John

[vigman]

No cheapies!


Vig!

[BlackNBlue95]

14.5 volts if good but is this at idle or at what RPM? Also what are you using to measure this the dash gauge or a volt meter? also amperage is very important to check.. I would also have the battery tested it could be sulfated and when the alt.. starts chargeing it puts up a "wall of voltage wich can burnt he alt up" basically check the batt damm gotta go teacher wants me.. ha

Okay guys and gals. I need some info. I posted earlier about the alternator showing low voltage a month or so ago. It was fine the next day and I let it be. I was going home the other afternoon and all of a sudden I get a high voltage light and check the volts and it is at 17.7. I immediately pull over and it settles back down to 14.5. I pull off again and as I rev the engine it goes back up again. I pull as much load as I can and go slow but it still was running high. I was a mile from the house. When I get home, the alternator if fire hot and the transmission is acting crazy. Was that from the vooltage problem and could I have burned something up. The computer seems fine and when I removed the battery cable and reset everything. I started it up and it ran fine with no SES light. The tranny acted funny though. I have to wait for an alternator till Monday. I did repalce with AC Delco and it is under warranty. It appears that the voltage regulator has gone bad in this one. Also, the parts guy at the Chevy dealer said I have to have the original receipt. Well, I don't. Can't find it. I do, however, have the credit card statement showing I purchased it. Has anybody else had to use this route before with GM. I hate like the devil to have to buy another straight out with this one under warrant just because of a receipt. Sorry for the long post.

Chris

[Edmond]

Chris,

Glad you went with the Delco. I learned the hard way and actually purchased a used one for $60 from a Vette junk yard. That thing lasted me 6 months and when it died last Sunday, I was fortunate to have it die just as my forward momentum carried me into my driveway!

So I bought a new one for $160 with a lifetime warranty. Called a Chevy dealer and said they wanted $500+ I should've known better than to ask the Chevy dealer; they wanted $6 for lugnuts, each! LOL.

[BlackNBlue95]

Originally posted by dabvette
Okay guys and gals. I need some info. I posted earlier about the alternator showing low voltage a month or so ago. It was fine the next day and I let it be. I was going home the other afternoon and all of a sudden I get a high voltage light and check the volts and it is at 17.7. I immediately pull over and it settles back down to 14.5. I pull off again and as I rev the engine it goes back up again. I pull as much load as I can and go slow but it still was running high. I was a mile from the house. When I get home, the alternator if fire hot and the transmission is acting crazy. Was that from the vooltage problem and could I have burned something up. The computer seems fine and when I removed the battery cable and reset everything. I started it up and it ran fine with no SES light. The tranny acted funny though. I have to wait for an alternator till Monday. I did repalce with AC Delco and it is under warranty. It appears that the voltage regulator has gone bad in this one. Also, the parts guy at the Chevy dealer said I have to have the original receipt. Well, I don't. Can't find it. I do, however, have the credit card statement showing I purchased it. Has anybody else had to use this route before with GM. I hate like the devil to have to buy another straight out with this one under warrant just because of a receipt. Sorry for the long post.

Chris

The trans could be related to high voltage especially if it's the 4L60E trans with the electronic valve body.. but please elaborate more on what the trans issue there is a possibility that whith the high voltage problem maybe, you could have some erratic line pressure and certanly this could burn up the friction materials in the trans..

[Edmond]

One thing I noticed prior to the alternator going out was that the gas mileage went down to about 12.2 and never rose above that. When I put the new alternator in yesterday, the mileage jumped back up to 13.3 in only 5 miles of driving. Is there any relation?

[BlackNBlue95]

Originally posted by Edmond
One thing I noticed prior to the alternator going out was that the gas mileage went down to about 12.2 and never rose above that. When I put the new alternator in yesterday, the mileage jumped back up to 13.3 in only 5 miles of driving. Is there any relation?

Could very well be related, the ECM uses referance voltages for certain sensors and a low battery or excessive voltage can throw things out of whack and can cause bad fuel economy as well as other drivability issues.. can even cause the ECM to store faulty trouble codes sometimes..
-Rick

Thanks for jumping in there, Rick. I will have to wait till Monday to elaborate on the transmission. I pray I have nothing to tell. It acted weird only after the voltage problem. I just made one heck of a clunk when I shifted from Neutral to Drive. Never done that before. I knew the tranny was electronically controlled and when I had the high voltage light, I also had all kinds of other lights. Airbag............etc

I will put the alternator on Monday and report back. I just hope if it is something electronic that It won't cost me a small fortune and it is something I can crawl underneat and repair myself. I'm praying for a normal operation with the new alternator.

Thanks.

Chris

I got my 2nd alternator from the chevy dealer and put it on the car. Took it out and noticed right away it was at 11.9v and then 12.1v. I thought this was ok. Then after about an hour, it was 11.9v and would go down to 10.9v with a full load.

Took care to mechanic as I was getting puzzled and he found that I had two wires wired backwards going to the alternator connector. He said one was a ground and the other sent a signal to the regulator. He said this could be why alternators going bad.
He says to repalce alternator again and said I shoudl replace the hot battery cable as it was very corroded. He's not a vette mechanic per say but does seem like he's knowledgeable.

After the switched wiring, and a full battery charge...I pick it up tp bring it home while I await the newest alternator. I get in and notice the battery light is dimly lit. Also the tranny won't go into 1st or overdrive. He said it was because of the low charging. My question is why wasn't the tranny doing this before the wires were switched. It shifted fine when I carried it to him yesterday with the same voltage readings. This stuff is way over my head. (electrical). Any thoughts?

Chris

[SPANISHVETTS]

No such thing as a coincidence. Charge light, transmission, hey the car worked before did it not? You should get a second opinion. If the wires were switched none of your alternators would have ever worked. WHO switched them to start with?

Disconnect all of the wires from your Alternator. Tape them up so they won’t short. Charge the battery full up and take a drive around the block. Did your problems go away? If so, it is time to get the GM service manual and sort the wiring out. We know it has been changed at least once. Your local NAPA store should test the alternator for free. While you are at it get the battery load tested. When you know all of the pieces are working start putting the puzzle back to gather. There are lots of in the know people here who will jump in and help you.

I just rebuilt my alternator. What the #*! was GM thinking when they put that cheep piece of crap on a Vette. I have always used Delco electrics because of the quality and ease of service. (Diode block screwed in, heavy duty brush holders, etc . Heck you could rebuild one in the back-woods with a Leatherman knife.)

Folks should not be so hard on the rebuilds. You can’t make chicken soup out of chicken$#!%. This alternator is junk from new. Ok for a Chevette not a Corvette.

I am looking at Delco marine alternators to find a case that will fit the Vette brackets with minimal modifications. If I can find one I will fab up a harness and post it here. The marine unit sells for less than $200. It can be rebuilt for less than $50. using a single socket wrench.

This looks like a good answer for folks that want to stay original.
http://www.alternatorparts.com/gm_al...grade_kits.htm

[BlackNBlue95]

Originally posted by SPANISHVETTS
WHO switched them to start with?

Disconnect all of the wires from your Alternator. Tape them up so they won’t short. Charge the battery full up and take a drive around the block. Did your problems go away? If so, it is time to get the GM service manual and sort the wiring out. We know it has been changed at least once. Your local NAPA store should test the alternator for free. While you are at it get the battery load tested. When you know all of the pieces are working start putting the puzzle back to gather. There are lots of in the know people here who will jump in and help you.
http://www.alternatorparts.com/gm_al...grade_kits.htm

I would try that fully charge the battery.. and disconnect all alt. wiring... leave as many accessories off and take it for a ride and see how the trans shifts.. keep in mind that if there was a problem before with the trans because of low voltage it could have easily burned up some of the clutches if the line pressure was too low... and that is some money.. trust me I'm rebuilding my trans myself.... (actually if you do it your self you can spend around 300 bucks.. not includeing the torq converter thats a heck of alot cheaper then a trans shop that wants around 1500+ usually) anyway just try that out... and see what happens....

just sounds weird that the wires would be switches I would consult a service manual just to double check... not that you Mech is wrong.. but just because it sounds odd..

-Rick

Actually, I can explain how the wires were switched. I replaced the alternator with one from Autozone about a year or so ago. When I was taking the connector off the bad alternator, I broke the connector. I purchased a new connector and pigtail from GM. That is where the wires were switched. I did it.

I will have the battery load tested today and the alternator to see if the mech knows what he was saying. He showed me the wiring diagram and said that I did have the two low voltage wires reveresed.

I'll try the above mentioned and see where I'll go from here.

Thanks.

Chris

[SPANISHVETTS]

Was the Autozone unit a rebuilt CS-130 Delco?
Did it ever work?
Check out the kit I posted above before you waste any more money on a new or rebuilt CS-130. I ordered one yesterday just to have a look at it. If the parts are up to the standard they claim this could be the answer to our C-4 alternator problems.