Battery blowing voltage regulators "why"

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big block

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Ok guys
answer me this. I've been blowing regulators for a while. Amp meter would jump wildly. It would burn up the electronic modules and other things. Finally just for the heck of it I changed out the battery with a smaller cca battery I fhad in the shop. Problem solved.
I just want to know what could be wrong with a battery to cause this? The battery always started the motor it never need charging and when ever I checked the voltage it would be 12.50 or better. I took it to auto zone where I bought it and had it checked. The clerk said the battery showed bad, but he couldn't say what was bad just that his machine said it was bad.
Any ideas?

big block
 
Measuring the battery voltage with car off does not give us information we need to trouble shoot. What is the battery voltage with car running? What is the voltage of the regulator case to battery (-)? What is the voltage battery (-) to chassis.
 
The voltage running was 13.67 volts. I never checked - to chassis because I don't think you would get any readings from - to -.
It wasn't a bad ground because I had a wire run from the regulator mounting screw to the alternator.
Thanks for the input.
 
Sounds like an internal short of the battery to me also.
 
On a valiant that I used to have, the ammeter wires melted and would periodically short to the metal dash frame while driving down the road. I would change regulators and alternators every 6-9 months.

After finding and fixing the wiring, I never bought another alt and regulator again...
 
Was your Vreg the old mechanical type (always state the car model and year)? I wouldn't think the later electronic Vreg (triangle connector) would be damaged by even 16 V input. Perhaps if the field control wire shorted to 12 V it could be damaged. If so, that might happen within the connector.
 
BillGrissom said:
Was your Vreg the old mechanical type (always state the car model and year)? I wouldn't think the later electronic Vreg (triangle connector) would be damaged by even 16 V input. Perhaps if the field control wire shorted to 12 V it could be damaged. If so, that might happen within the connector.
Click to expand...

Like Bill is eluding too, there are 3 voltage regulators. The points type, The I think 70 and down retrofit one for electronic ignition and the 71-up stock(I think).

What year is your car or is it retrofitting to electronic ignition? We need to know more.

Tee points type will blow if used on electronic ignition converted cars. It physically wont interchange with factory electronic ignition cars.
 
So if you change to electronic ignition it can cause the VR to go bad? I am having a problem with my regulator getting really hot??
 
big block said:
Ok guys
I changed out the battery with a smaller cca battery I fhad in the shop. Problem solved.
I just want to know what could be wrong with a battery to cause this? I took it to auto zone where I bought it and had it checked. The clerk said the battery showed bad, but he couldn't say what was bad just that his machine said it was bad.
Any ideas?

big block
Click to expand...

It has an internal intermittent short, batteries can do all kinds of things
like that. They can have/develop cracks in post connections & cell bridges that work
one second and not the next, pass a test and then not start 3 tries later,etc.
The alt. can put out 18V or so full fielded,if that happens repeatedly,even if
briefly you're going to burn stuff up.I've seen many batt.s subjected to shocks,as
in accidents, and if it required any serious repairs the odds were 50/50 it would
last.Even if it showed -0- damage and on the opposite end of the car I would
demand a new batt. from the ins. co. even if I had to pay it "pro-rated" for that
reason. Given you state "problem solved", get a new batt. dude, or make them
eat it if it has any warr. left. :coffee2:
 
KitCarlson said:
If grounds good, likely an intermittent battery cell short. +1 TrailBeast post.
Click to expand...
Another possibility: Disconnecting a battery while the alternator is running is a known cause for taking out regulators. Some systems were more prone to this than others (the 60's-70's Ford mechanical regulators would go out almost every time), but at the moment the battery is disconnected, the voltage shoots way high (like 18-20 volts or more) and that will do it. Could have been an intermittent connection like above, or an intermittent inside the battery. This would explain the surging ammeter too; the voltage surges would cause that.
 
Mckibben said:
So if you change to electronic ignition it can cause the VR to go bad? I am having a problem with my regulator getting really hot??
Click to expand...

No, I've ran electronic ignition on many 67-69 a-bodies with the original voltage regulators with no problems.
 
I agree, I think its a short somewhere hidden too. Im currently having the same problem, both with all original regulator/alternator/points, as well as after upgrading to electronic on a 66A. It was all either new or rebuilt. I switched the alt/reg to a set from a 72 Dodge with new Bosch battery, and it worked great with points for several months, but at some point the battery swelled up and the alternator fried. Gauge twitching and battery overcharging. I replaced it all again with a new distributor and all worked great for a while. Now with the new ignition kit, the gauge is twitching once more, the regulator burned up and replacement battery is leaking.

This also happened to the original owner before I bought it, so I'm starting to think that replacing these electrical parts is just a temporary solution. Next is a search for a higher quality regulator, and thorough inspection of all wires because something else seems to be the problem.
 
I don't know. Intermittents are "hell" I've written a BUNCH of charging systems on this site. The "usual suspects."

Of course you need a good battery. ALSO SUSPECT the battery mounting, the types of roads you travel (bumps / washboard) IE possible damage to the battery from shock. The battery must not bounce around "in there" and move around in the tray. It must be solid and tight, or you will "beat it to death." (Bungie cords don't hack it)

Field current. Check alternator field current and endeavor to buy good quality regulators. That is harder now, even at NAPA, who should have their heads dropped in shame. Echlin and Standard / Blue Streak at one time were "the" quality standard. No more

"All other" wiring considerations...........

Might be time to put one or two accurate voltmeters "in the system." If you mount a couple under the dash, you can run wires to different points at different times. One direct to the battery, and move the other around "once a week" LOL

Make sure the charge wire is large and has GOOD terminations, which is the big downfall of OE wiring, and IS the subject of the famous MAD article

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

If you do nothing else, even temporary, run a nice big huge charge bypass wire from the alternator stud direct to the battery. This will require a voltmeter, as your ammeter won't work. One way to do this with common available parts is to parallel about 3 no 10 wire, as you can get terminals and wire from the parts houses.

Since you are having regulator problems, this might indicate a short right in the field circuit. Maybe you should inspect that field wire THE ENTIRE LENGTH from the regulator F terminal to the alternator.

Of course the regulator MUST be well grounded.

And, double "triple" check voltage drop problems.
 
Ok Guys I finally fixed the problem. I changed the battery. I never would have thought it , but the batt was the problem. I took it to auto zone and had it checked. It showed bad on the electronic checker. They could't tell what was wrong just that it was bad.
From what you guys say it has a short in it. I have let it set for a solid week and checked the voltage and it is 12.56 volts. I thought if a batt had a short in it it would die, but I have learned differently.
I thank you guys for all your help and input.
Live and learn
big block
 
A short is accumulation of flaked off plate material on the bottom. It might come and go with vibration and bumps. There is also an open when the internal series connection become intermittent due to sulfation or loose crimp.

The short may max out the field, trying to raise the voltage to normal with one less cell. The open also leads to spikes in voltage and current.

Measuring a battery unloaded is not a very good test, because current is low, up the current, for starting, the open problem may show.
 
big block said:
... I took it to auto zone and had it checked. It showed bad on the electronic checker. ...
Click to expand...
A small data point. In the last 2 years, I bought ~4 new batteries from Autozone. I recall taking 3 in on one day. Just coincidence so many came due at once among my 7 vehicles and trailer, and they aren't cheap these days. As I recall, about 3 failed within a year or so. My Battery Brain started tripping (have on most cars) and Autozone tested them as "bad", i.e. wouldn't hold a charge. I recall one was just 5 months old. All were free warranty replacement (I always buy the gold-top ones). Must have been a battery factory started dropping the ball, maybe Billy Bob on the night shift did something wrong 10,000 times. Probably not confined to Autozone since there are maybe 2 battery manufacturers in the country, sold under ~20 brand names. So far, none of the replacements have failed.
 
Or like when I got a string of 3 bad DieHards from the same Sears store. I finally 'connected the dots' that all of them had a 2 marks spaced apart the same distance in the sides of the opaque plastic cases..... like the plastic had been compressed. All of them were in a batch that musta been knocked against something in shipping or handling somewhere along the line, and probably had cracked/broken plates causing the symptoms of internal shorts. (One shorted itself while sitting overnight, over heated, burned to top off and leaked acid all inside the trunk of my 1st race car!)
 
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