I've been smelling a STRONG sulfur smell the last couple times I have driven my '57 and I couldn't pinpoint the source. Tonight I drove a good ways and when I turned off the truck I could hear a sizzle… I traced the sound to the battery. It was smoking and bubbling. Not good. I just replaced the alternator a couple weeks ago with the one that Autozone recommended. Any ideas?
sure, show us a picture of the alternator, and maybe describe how it's wired up. Could be that something is amiss.
I hope thats not the volt meter reading when its running. What does it show when you are driving down the road? Shouldnt ever be any more then 14.8V. If it does then you have a regulator problem. Is your regulator internal or external?
So after looking around online I'm thinking the genius at the auto parts store sold me a high output alternator that is the wrong application for my engine… maybe it's my fault for not knowing what alternator I needed instead of trusting the Autozone employee.. I should go swap it out I'm thinking… https://www.powerbastards.com/proddetail.asp?prod=7127-9-220-HD10-67
A higher output alternator can provide more current when needed, but if it's working properly, it will still run at the proper voltage. That's a 63 amp alternator, which should be fine for your truck. but also, how old is the battery? You really need to see what the voltage is when the engine is running at a fast idle, as he said it should be between 13 and 15 volts. If it's higher, then the internal voltage regulator is probably messed up, or there is some other internal problem with the alternator, and you need to replace it.
The alternator plug say internal reg. I pay a little more for my alternators. I buy from a local rebuilder.
The gauge pegs out at 16 volts. When I turn the truck on it pegs at 16 same as when I'm driving down the road. I really didn't pay that much attention to it because it is all new and I just assumed was working correctly. So should I swap the alternator out for a lower voltage model?
the alternator is defective. It is the right model. you just need to get one that works. first though, make sure the red wire on the plug is connected to the red wire that is on the screw terminal.
Years ago I replaced the alternator on my Corvette with a "rebuilt" one from a parts house. Immediately upon starting the car the volt meter pegged and the dash lights lit up so bright they almost blinded me. Obviously the internal regulator was bad. I took it back and got another one and no problem after that. I think you have the same problem.
A charging system that is working correctly will only put out enough voltage/amperage/wattage to run whatever is using electricity and a little extra to keep the battery charged. It can't put out too much and boil the battery unless something is wrong. The voltmeter should never peg out like you are seeing under normal conditions. Take that alternator back to the store for testing and most likely replacement unless you have miss wired it. The type of alternator you have has a tab for testing that can bypass the regulator making it do what you are seeing. My guess is that the test tab is grounded out somehow internally. Search "GM alternator full field test" for details.
Doesn't matter if it is high output or not, as long as the regulator is working properly. Sounds like yours is not. Alternators from your local parts store are a crap shoot, I have had them fail right out of the box, especially the rebuilt ones. Swap it out and see what the next one does. Don
Me too, but from another parts chain. Over about 6 months 3 of them failed and I took them back. The "expert" behind the counter said "Ok, I will give you one more, but that is it, you have something wrong with your car !" So I told him to test the new one on his machine before giving it to me. He took one off the shelf, tested it and set it aside. Then he pulled down one more and tested it, set it aside. Finally, on the third attempt, he got one that would work right. As he handed it to me, I said "So what was that you were saying about something being wrong with my car ??" Rebuilders fix the most obvious problem when they rebuild them and stop there. There can be secondary problems that they miss. Now I only buy brand new parts, but sometimes even those are bad out of the box. Don
It should charge between 14.1 and 14.5 volts. Check all grounds while you're at it. I use local shops to do my starters and other electrics. So they know me and so far have never sold me something bad. One old guy did my stock car starters and no matter how hot the engine got, it always started.
Check the ground to the battery. If it is loose the alt will put out more voltage and boil the battery.
As many have said, bad alternators right out of the box. I gave up on those and buy new ones or take them up the hill to a reliable local rebuilder-an older guy with a one man shop-knows his stuff. Have had good luck with Powermaster alternators.
I'm running the older 1960s style alternators with the external regulator on a couple of mine...using old used regulators...they seem to do fine. Maybe I'm just lucky
I went back to Autozone and swapped the alternator out for a model # 7127-12M that puts out 43 amps instead of 63 amps like the one I had. They gave me the wrong one the other day. The one I had was rated for heavy trucks and equipment. I will put some miles on it tomorrow and see...
that and you know electronics , to some electronics are a mystery as is something you cannot see , to people like you or my dad ( also A EE ) its second nature .. to people like me I tend to burn up a few bulbs and exploded a few others before I got the hang of it ..
amps has nothing to do with the the voltage it puts out , the regulator was bad in the old one causing it to stay on , kind of like a broken light switch . if your battery has a problem keeping up then you will need the higher amp unit . but if your a bare basic ( lights heat only , radio ( am /fm no amps ) you should get by with the smaller unit . just remember you will have to run the vehicle 10 -15 minutes per start to keep it charged up .
I am amazed they will "work" with you, on electrical parts, no matter what the circumstances.. They have signs all over " No return on electrical parts" (where I live, NAPA, O'Reilly's, Autozone. Joe the Rebuilder,") and others.
ussually thats meant for small things like sensors ,relays and switches , you wouldn't believe how many people try to "rent or borrow" a part to see if that is the cause of there problems instead of knowing what to look for or how to test the part . and we have had a few that tried to pass off the old dead part as the just bought one and get a refund on it ..
A return isn't the same as honoring a warranty. and yeah, the new alternator working properly has nothing to do with the current rating. It has to do with having a good voltage regulator inside of it.
I am a novice when it comes to electric. The guys at the parts store didn't know much more than me but we tested the voltage with the other alternator on and it was right at 16 and with the new one it was right at 14. I will run this one for a few days and see… Thanks for the help
Some of us answering your questions are not novices with electric stuff....we've been through this many times.
I worked at one of those discount auto parts stores for a while. NEVER leave the store with a rebuilt alternator or starter without them checking it out of the box first. Like others have stated, we have had lots of them bad right out of the box. When they rebuild one, they only replace the bad parts and clean the rest, its not really rebuilt, its overhauled. And sometimes they have the wrong unit in the box. Do not trust the store.
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