I know there are a lot of posts on C4 alternator problems, and I've read through a lot of them. I purchased my 1986 Corvette 2 years ago. It had a Delco Remy rebuilt alternator on it the previous owner installed around 2015. It stopped charging the battery about 6 months after I bought the car. The only alternator in town was a rebuilt Auto Zone alternator, which I usually would never purchase, but it was the only one in town. About 30 days later the nut and pulley came off the alternator and the belt came off the engine while driving. Not fun, and I refused to put it back on. I ordered a new BBB Industries stock alternator from Rock Auto. That worked for about 5 months and stopped charging. I didn't see any casting marks, but I'm guessing it was a Chinese alternator. I believe the regulator went bad in it. I call Rock Auto and I got another warranty replacement unit. Everything seemed to be working fine, and it charges around 14 volts while driving. I recently received a code 33 (MAF voltage high) followed by a 53 (alternator voltage spike above 17 volts) after about 6 months. I reset the computer and keep the voltmeter on while driving. I never see it spike above 14 volts, but the code 33 & 53 came up again the next time I drive it. I took the alternator into O'Rielly's, and it tests bad. It failed the PLFS and feedback frequency test. I figured the alternator voltage spike caused the MAF error code. I then put on a new spare WAI alternator that I had, which almost looks identical, but has a different sticker on it. I had the WAI alternator tested twice before I installed it, and it tested good. I've seen in the forums some guys replacing alternator after alternator and I feel like I'm heading in the same direction. I don't know if it's bad Chinese alternators or a problem with the car. I started looking into upgrading the alternator to a higher amp unit, when I spoke to this old mechanic. He said Chevy grounds were bad in those years and a bad ground will kill an alternator regulator in no time. He suggested that I run a wire off the alternator ground wire directly to the negative post of the battery and for me to run a second hot wire from the alternator and run it directly to the positive side of the battery with a fusible link in it, which would allow for more output of electricity. This idea sounds logical to me, but I'm not fond of getting away from stock like this. What are your thoughts on this? Should I get a Power Master 140-amp alternator and install that, just see how the WAI alternator performs and go from there, or go ahead and make the wiring changes that were recommended to me? I was also looking at a 200-amp alternator at Corvette Central that has a heavy-duty regulator. Has anyone had luck with this one? I called them and they told me it was a Delco Remy. I appreciate any advice that you can give me.

 

Truthfully I think you're the victim of dumb luck, you can test the bad ground theory real easy by doing what he said but use a standard old test light if it lights you have a problem

 

What do you mean by the standard old light test?

 

Might do a google search for alternator rebuilders in your area. I would trust a local rebuild over a China new myself.

 

 

Got it. I should put the continuity checker on the negative alternator wire and place the other end on something grounded to make sure there's a connection, right?

 

We do have a local rebuilder, which I've considered. They can rebuild the Delco Remy that I have and bump up the amps to 130-140 for about $200. The only thing holding me back is word of mouth saying they may possibly use some components from China.

 

ACD parts are available for your rebuild so I think that might be a generic statement, I bet you could specify ACD ONLY

 

Go with the local rebuilder. Unless you're running some kind of bass-thumping sound system, leave the amps stock. You don't need anything more than that. If you're considering a lighting upgrade, go with LEDs to take the load off the alternator. Talk to your rebuilder if you're worried about Chinese parts (as you should be...). They know the difference and also the failure rate of the Chinese components. I've had good luck with the local guys with all my vehicles and boats.

 

Have you considered upgrading to a CS144

 

My CS144 is still going strong after upgrading 20 years ago.

 

What is it with C4 alternator pulleys flying off? My '89 did this not two months ago, and I replaced the Autozone reman alternator, which was trying to push the rear bearing out of the back of the case, with what I feel is probably a just-as-shitty AC Delco unit I got from Rock Auto that is made in China.

 

In response to jframe . The pulley nut threads looked stripped on mine after the pulley came off. Maybe they're putting the pulley nuts on to fast and cross threading them at the rebuild factory. I never get rebuilt anymore if I can avoid it. This happened to be the only alternator in town, and I wanted to get my car running. This was a big mistake that almost cost me an engine. I let my 19-year-old son drive the car one night and he calls me from an In-N-Out Burger parking lot. He tells me he pulled off the road and smoke is pouring out from under the hood. He said the car became hard to steer about 5-10 minutes before he stopped. I go down there and pop the hood. The alternator pully is sitting detached on top of the engine and the serpentine belt is still in place, but loose enough to prevent it from driving the water & steering pump and etc. I notice antifreeze sprayed all over the radiator cap and the surrounding area. It wasn't smoke that he saw it was steam. My son said no warning lights for overheating came up. I guess he pulled it over quick enough to prevent serious damage to the engine. It must have gotten hot enough to pop the radiator cap safety release. I had the car towed home and I replace the alternator. I refilled the radiator and kept my fingers crossed. There is no antifreeze in the oil and no compression bubbles in the radiator. It also doesn't lose antifreeze. I replaced the spark plugs a few months after that incident, and they all looked good. This happened about a year and a half ago. I think I got lucky, and it didn't crack the heads. I went through all of this for a poorly rebuilt alternator.

 

In response to braeburn22 . Yes, I'm seriously considering an upgrade to the CS144. My main concern is the rear brace.

 

I have had my cs144 fitted for over 6 years without the rear brace without any issues, but if you clock the cs144, ie rotate the rear case of the alternator by 90 degrees anti clockwise, the standard brace will fit, my 1989 didn't have to brace fitted to the cs130

 

I posted a thread covering my installation of an LS-era AD244 alternator in my '89, with the primary objective being to replace my failed stocker with something more robust and resistant to the high underhood temps in there.

In addition to the alternator itself being more heat resistant than the CS series, the elimination of the exhaust header heat delivery rod (aka the rear brace) to the rear bearing area was a very welcome advancement.

Fabricating the necessary bracket was a bit of work but I'd say well worth it and also really gratifying.

https://www.corvetteforum.com/forums...upgrade-2.html

 

I'm curious, are any of you that are reading this thread still running a CS130 alternator?

 

Thanks for sharing braeburn22 . I've read in various threads that some people that leave the brace off have cracking problems with the main mount and others do not. The brace connecting the alternator to the exhaust manifold seems like a poor design. It's transferring the heat directly from the exhaust manifold directly into the back of the alternator. This could be one of the reasons I keep burning out the regulator/diodes on my alternators. The rebuilt Delco/Remy that came with my car when I bought it had about 20,000 miles on it before it failed. I have records when the previous owner replaced it. The stator and inside of the case are scorched black. I think these Chinese alternators are not built nearly as well, and maybe the heat is what's killing them so quickly. It seems like the alternator is mounted well enough it shouldn't need a back brace. I've had a lot of other cars and none of those alternators had a back brace. I'm heavily considering installing the CS144. You made me a little more comfortable doing it.

 

Thanks for sharing ThickLizzyVetteswerv . That's a really nice professional looking brace that you manufactured.

 

Thank you for the picture RWDsmoke . A picture is truly worth a 1,000 words. It looks like you manufactured a whole new alternator mount that looks great and professionally made. I'm looking at your positive charging wire on the back of the alternator. It looks like you're using the original charge wire, and you added a second wire to accommodate the higher amps. Is this correct? Where did you run the second wire if this is correct and what guage wire did you use? Directly to the positive battery post or to the positive jump/junction block next to the battery?