Thanks again "ihatebarkingdogs" I want to keep this new 32 year old Vette as original as possible. I ordered a new voltage regulator and am going to replace that first and hope it fixes the problem. By the way if it helps anyone, the Airtex/Wells regulator on the "Rock Auto" website has a great instruction sheet showing how to replace the regulator.

 

We have yet to see the photos!

Detailed pictures of the engine please as it will help us NCRS wannabees.

 

IF you rebuild the alternator, you can still have the same item for originality, assuming that the alternator comes with a matching serial number which I don't know if it does or does not. Does it? IDK.

 

I'm back working on this problem after life got in the way for a couple weeks. First of all thanks for the great advice about the "webbed" voltage regulator. I have seen vendors selling those for my application. So this was good info to know. The voltage regulator I'm looking at purchasing is an Airtex/Wells Part #1V1032 from Rock Auto. This is one of the few I've seen that specifically states it is for a 120 amp alternator which mine is. Looking at the picture it looks like the two terminals are bridged together just as they go into the ceramic. But it is not as obvious as the webbed regulators which have the bridge a little higher up on the terminals. Can you tell me if this regulator will work or recommend what will?

 

These alternators are super easy to work on!! Since this car has been sitting so long, I'd first try an internal clean-up of the alternator. The regulator operation depends upon good electrical contact at the three "pads" at the three mounting screws. Use some 1000 grit wet-or-dry sandpaper to polish these pads on both sides of the regulator module, on the brush block, and on the ground pad on the housing, then put a little di-electric grease on these points to prevent oxidation. Be sure the nuts on the stator windings are tight on the power diode block.

I like to add a ground wire between the alternator case and chassis ground to assure a good ground connection, rather than trusting the mounting bolts to provide the ground connection, but I'm sure that's not NCRS approved!

 

Thanks. That's the info I needed. I'll go with the Delco D680. One more thing I failed to mention when the alternator was overcharging. I had a battery charger hooked up and forgot to unhook it when I started the car. After I cut the engine off I pulled the voltage regulator plug from the alternator, cleaned the terminals, and put it back. Then when I started the car again the alternator would not charge at all. The engine only ran a couple minutes, but could have leaving the charger hooked up while the Vette was running have done additional damage to the alternator? Maybe burning out the Diode and/or the Rectifier and that's why it's not charging now. Or should I just try replacing the voltage regulator first and see if that fixes everything. I hate to tear into the alternator more than one time. Any advice?

 

haven't seen anyone else suggest this yet, so I will (even though it's slightly off-topic):

fuelinjectorconnection.com will take care of your injectors for you. They're almost certainly clogged at this point, I sent mine off and within a week got them back, good as new. One, they're still your original injectors (which, with this car, could be a consideration), and two, it's a lot cheaper than a new set. Ask for Jon.

It's amazing what a good injector cleaning will do for this car.

 

Thanks Bfenty. I may have to try that. I just cranked the engine again this morning after installing a new complete fuel pump sending unit and fuel filter. I wiped the inside of the fuel tank as good as I could. I didn't want to remove the whole back end of the Vette just to get the fuel tank out. Tank looked pretty good inside after I wiped out - no surface rust that I could see. Then I put in 2 ounces of Sea Foam & 2 gallons gas before starting it. It ran slightly better than before, but is still missing & not smooth at higher RPMs and idles very rough. I'm assuming it's the fuel injectors all mucked up.

 

Hello VRACER99,

I am curious. You mentioned that after you started the car that it started overcharging and the battery was spitting out electrolyte through the vent tubes. Your words were "It overcharged the battery so bad it blew a lot of battery acid out of the vent tubes". How much acid was expelled from the battery, teaspoon, tablespoon?

I am assuming this is a lead acid battery right? Nothing unusual about it? Is it a "Maintenance Free" type cell where you can't access the electrolyte or can you open the caps and refill the electrolyte? A lot of Maintenance free batteries still allow access to the electrolyte.

You mentioned this was a "new" battery that you just installed, Brand new? What brand is it? If indeed it is "Brand New" you can probably re-fill the electrolyte (available at most good auto parts locations) with additional electrolyte and save the battery. Do not add electrolyte to a battery that anything but "brand new".

You mentioned later that you had a charger on the new battery prior to starting the car. At what rate were you charging this cell and for how long?

In the old days they used to tell people that if you have a battery charger on a battery and then start the car that you "could or might" damage the alternator or the charger.

Do you have any idea what the charger was doing when you started the car for the first time? How long had it been attached to the battery? How many amps is your charger rated for? Any idea what the Voltage or the amperage it was charging at? It sounds like the battery was fully charged and the Battery charger was still connected.

If the battery was new and you charged it up prior to starting the car and was disconnected before cranking to start your alternator. Your alternator would have seen a high enough voltage quickly after starting it and it should have slowed down the charge to a mere trickle charge as the battery was full. Having the charger on it when starting it might have been the biggest problem. When you crank the car it can pull several hundred amps easily, this immediate drop in voltage would cause the battery charger to go to max charging pushing the battery voltage up very quickly. Then you add in the functioning alternator and it is trying to see what the battery "needs".

The battery is full so the alternator puts out virtually nothing as the battery it is monitoring doesn't need charging.

Before tearing into the alternator I would check the voltage of the battery with a good multimeter and monitor the voltage carefully when the car is started with NO battery charger attached to it. The regulator in the alternator was just doing its job stopping any more current from going to a fully charged battery.

I have found that a lot of over the counter battery charges have higher set points than the folks at GM used in their regulators.

I am not so sure that you need to replace the regulator at all. The alternator has few mechanical parts and little to go bad with no usage. Since you ordered a new regulator at this point you should be safe. After testing the car without any outside charging source if you determine that you need to install the regulator, clean the contacts with a pencil eraser as it is not very harsh on copper contacts.

I think that the "overcharging" was due to the charger you had attached to a running car with a functioning alternator and regulator.

When I read your initial comments I could not understand why your battery would spit out electrolyte within a minute or two with just a cars alternator charging it. It takes a long time charging a battery at high enough rate to get the electrolyte just to start bubbling. To get it to spit out the vent tube would require a long hard charge.


I apologize for asking all these questions. I tested batteries for many years in my job. Batteries are a strange creature, each manufacturer tries different chemistry's and no two are alike.

As far as the injectors go I have had great success using the 3M brand injection cleaning system. It goes in through the schrader valve on the fuel rail and the car runs on the material in the can for 8-10 minutes leaving the injectors very clean without dismantling your car. If you have about 10 gallons of gas you might even try BG44K fuel cleaner as that stuff really works. Before you go to far you might check your engines for being grounded. If there is any corrosion on the ground strap this could make more trouble for the engine and its sensors.

I wish you the best in resolving your cars issues.

 

Thanks for all your effort and suggestions trying to help me. I don't mind all your questions at all if it helps to figure out & solve this problem.


OK to answer your questions. The battery is a MAXX-75N, 700 CCA, 875 CA. It's one I had in another car and is 2 years old. Just as a side note I keep this battery on a maintainer since that car is not driven very much. It's a "Maintenance Free" battery and the top appears to be sealed where it cannot be pried off to check or add electrolyte. The battery was at full charge before I put it in the Vette. But I figured I would have to crank the Vette a lot before it started. So to insure the battery was at full charge I had it on the 6 AMP charger about 15 - 20 minutes before starting the engine. Then as I said I forgot & left the charger connected when I started the engine. The engine had run about 2 minutes at 2000 RPM when I noticed the red warning light on the dash gauge & it showing 18.4 volts! When I got out I noticed the battery fluid on the floor. On closer inspection there is a small rectangular vent tube on each side of the battery. The fluid had puked out these tubes to a distance about 6" to a foot away from the battery. So it spit it out pretty strong. Hard to tell but I would guess at least a tablespoon full or a little bit more total fluid spit out. As I said, the battery was fully charged but I still had it on the charger about 15 - 20 minutes before I started the engine. So I really didn't need to have the charger on it at all. I just did it to insure the battery was at max power in case I had to crank a lot to get the car started.


I think all would have been OK if I had just remembered to unhook the 6 AMP charger before I started the engine. Now I'm worried I may have damaged something else in the charging system other than just the voltage regulator. When I started the car again after I cleaned up all the spilled electrolyte the alternator then was not charging at all. But I'm thinking like you. What would cause the battery to boil over in such a short period of time. I remember several years ago I accidentally left this same charger on a battery overnight and it didn't boil it over. All this is a big mystery to me. But my main concern is if this could have damaged any other parts in the alternator or the computer.

 

Hello again VRACER99,

So the Battery is one that has been kept charged up on a "maintainer" charger. Is your maintainer a simple harbor freight type unit or did you spend $50 or more for it? The cheaper maintainers do not "float" a battery at a very low current based on the batteries voltage. I have a cheap one that I used on a brand new Interstate Battery and in one winter season (3 months) it boiled away all of my electrolyte and destroyed the battery. That charger was rated at one amp, it continuously dumped one amp into the battery no matter the voltage. This is why it killed my battery.
A good maintainer is a real "float charger" and it will sense the battery voltage and reduce the current (or just turn off the charging circuit until another voltage set point is hit) to a very low level keeping the battery at below 14.7 volts for a flooded lead acid battery.
If your charger does not have the ability to float the battery then it is probably over charging it. Your six amp charger would make a fully charged battery get overcharged if that charger is not an "Automatic Charger" which usually means it will taper the current as the voltage gets closer to the magic 14.7 number. Does your charger let you choose what type of battery it is being used on? A lot of the newer chargers require you to choose what type of cell you are working with. I have a small 2/6 amp charger and it lets me select whether it is a "Sealed" (Valve Regulated), "AGM" (Absorbed Glass Mat) or "Standard" (Flooded Lead Acid or "FLA") cell. I have seen many automobile batteries that appear to be sealed and are just difficult to open. The Picture of the MAXX-75N appears to have two plastic covers over the cell openings. I would guess that it is possible to get access to the electrolyte. IF you could open those covers I would, check the electrolyte level and add any distilled water needed to bring it back to the correct level for the cell. Usually there is a indicator of the "Full" level of electrolyte. Try to remove the caps and check if possible. DO NOT OVERFILL THE BATTERY...

I am curious how your battery went to the point of expelling electrolyte so quickly after startup. It would take a normally "fully" charged battery quite a while at a high rate of charge (15-20 amps +) to build up the pressure needed to expel any electrolyte quickly through a pressure relief valve. This would depend on the battery of course, some maintenance free batteries have a pressure relief valve that has to be opened to expel anything.
I suspect from the price and brand of the battery that this is simply a standard Flooded battery with no pressure relief system built into it. This is good as you should be able to replace the electrolyte lost with some distilled water.

When your car started up with a fully charged battery on a charger the voltage drop at cranking would have made the charger put maximum amps out (6 amps) almost instantly. With your battery being roughly 90-100 amp hours ( in capacity) this still does not make a situation where you would see electrolyte being spit out. Your alternator's regulator has a sense wire attached to the battery voltage so it can charge the battery most effectively. As the voltage of the battery goes up the current will start dropping. When your alternator saw the battery voltage the regulator would have produced nearly no current as your battery appeared to be fully charged. So again how did the battery get fully charged and pressurized so quickly?
It is possible that your regulator is in fact bad. There are many cases of batteries exploding in cars while driving due to massive overcharging. I saw a C4 Corvette with acid burns on the drivers side running down low and back, it does happen but it is rare. When batteries explode they frequently have a blockage in their venting system.

Since you have the new regulator I would install it in your car and then monitor the battery voltage very carefully when you restart the car. If you have one use a multimeter with a Min-Max function where it will show you the lowest battery voltage while cranking and the maximum voltage while charging.
Whatever you do, do not unplug or do anything to the alternator while running. This will cause problems and require new parts.

It is unlikely that the brief "over voltage" (18.1Vdc) did anything to other systems in your car. Have you checked all the battery connections like where it connects to the alternator and other cables for corrosion? My car sat for a couple years all closed up and I had a heck of a time getting the electrical gremlins to go away. I went through my entire electrical system and cleaned ever major connection for battery (12 Vdc) and the Ground (0 Vdc). I had voltages where it was over 2 volts below the battery voltage before and now I have full battery voltage at all the major junctions in my cars electrical system. Just remember that on these cars the ground being 0 Vdc is just as important as the battery 12 Vdc is. These cars use many sensors and their being grounded properly is essential for their proper operation.
After my electrical system started working properly all of my accessories work great. The windows go up faster now, virtually every major system was being affected somehow before I fixed my electrical issues.
Just because your car has such low mileage does not exempt you from these other electrical issues. Corrosion happens no matter the age. Unless the car was in a temperature controlled, de-humidified environment it is likely you will have a few issues happen.

A fully charged Flooded Lead Acid battery like yours should be in the 12.6-12.8 level when left unhooked from the car and alone for a few hours.

If your battery is low on electrolyte you might have a situation where it's voltage shoots up when charging it. This is because of the lost capacity of the battery. I would seriously think about getting the battery you used tested and let us know what happens. On a battery that has been over charged like my Interstate was you see an interesting development. If I attached it to a 6-10 amp charger the voltage would just shoot up to the over voltage point in a few seconds of charging on a non-tapering charger. This is why I want you to have that battery tested. I am curious about its capacity at this time and whether it played a hand in you problem.

I am off to install new weatherstripping on my freshly painted 1988 C4 so I wish you the very best in solving this issue. Good luck and have a great day!