Regulator keeps blowing

[keith88]

Hi guys it been a while since i posted been driving it around having fun. 2 weeks ago i was messing with the voltage regulator because a volt meter said i was charging to high at 15.2 I have the box type that the cover comes off and i took it off and checked the gap and readjusted it so it was giving me 14.5 drove it to a show and noticed that the amp gauge needle dancing around a bit but it settled down when i drove it a bit, went there and back fine but I decided to buy a new one just to be safe . Well when i put the new on in it blew the wire under the cover so i put the old one back in and it blew that one to  it seems to be the feed side wire connected to the male connector or the ING side that blows from looking at the connectors underneath the regulator. Any ideas what might be doing this? I also replaced the alternator.,but every time i put a new regulator in it immediately blows.

[c00nhunterjoe]

Is the car wired bone stock? Does it do it with the key off or is the key on when it pops?

[keith88]

As far as I know its wired stock there has been some wire replacement that you can see but it was all working for the last 4 years ( I have only owned for that long) before this happened the week before last. As far as when it blows i never thought about that and really not sure i never had the cover off when it was on the car to see for real.

[Pete in NH]

Hi,

Check the green wire from the regulator to the alternator field and make sure its not being grounded somehow. If you have an ohm meter, disconnect the green wire at the regulator and measure the resistance between the green wire and ground. You should see 4 to 5 ohms resistance, this is the field winding in the alternator. If it is zero ohms that is your problem. It could be a pinched wire, burnt off insulation on the wire or a defective alternator. Also, on a 69, one alternator brush is grounded and the other connects to the green wire. Some lazy rebuilders use the same flag terminals on both brushes and if you connect the green wire to the wrong one you blow the regulator, you have a 50-50 chance of connecting it wrong.

Good luck and let us know what you find.

[stripedelete]

Sounds exactly like the problem I was having (stock 69).    I ignored the recently rebuilt alternator as a possible cause.    Wish I hadn't.

[keith88]

The alternator is new and been tested.

[keith88]

OK here's a picture of which wire ...seems to be on the IGN side  and that it really not even getting inside yet if that the direction it comes in not sure on that... I did find a half broken GREEN wire (coming from the alternator)not sure if that would cause it I replaced it still looking at wire that go to it so far haven't found a bare spot.

http://s236.photobucket.com/user/cylon75/media/thumbnail_20181018_144645_zpspjivr3km.jpg.html

[keith88]

Which way will the current flow though the regulator the IGN side or the FLD side that will help me on what side the short could be on.

[Nacho-RT74]

On mech reg/single field alts:

Blue wire comes from ign1 ( RUN ) circuit. Green wire is the output from reg up to alt brush prong, being also a positive source like the input, but regulated.

On elect reg/dual field alts
Blue wire as previous years comes from Ign1 ( RUN ) circuit. Green wire is now NEGATIVE regulated source to one of the alt brushes, while the blue circuit runs also to the other alt brush. Both poles are wired on these.

If your car still have the stock mech reg/single field alt, a green wire grounded could cause very well a short on reg up to burn it up. A short on blue wire will make blown the fuse link and burn several other places of the wiring ( depending on how much takes the fuse link to blown )

On elect reg/dual field system, a grounded green wire will cause a full fielded alt, so high voltage output from alt

[Nacho-RT74]

OK here's a picture of which wire ...seems to be on the IGN side  and that it really not even getting inside yet if that the direction it comes in not sure on that... I did find a half broken GREEN wire (coming from the alternator)not sure if that would cause it I replaced it still looking at wire that go to it so far haven't found a bare spot.

http://s236.photobucket.com/user/cylon75/media/thumbnail_20181018_144645_zpspjivr3km.jpg.html

That reg is easy to fix. Just replace that wire section. Maybe is still in good conditions aside that wire cut if didn't get time to get another damage inside. It worked like a fuse LOL.

It seems certainly you have the green wire grounded somewhere because the cut wire seems to feed the output terminal to alt field... green wire itself or alt brush grounded

[keith88]

OK been using and old one and just replacing the wire to test with.. ( I dont have to start it only turn the ignition on)- with green wire off alt still blows, with a wire from directly from Alt to regulator (by passing the harness) still blows, and when i remove the green wire from the regulator and leave the push on side on it also blows .....Help Im confused!!

[Nacho-RT74]

Something down the reg is getting touch with chassis/firewall ? Some old regulators gets exposed parts underneath them

[keith88]

Mine is like that but nothing seems to be hitting the the firewall  and its done it on 3 regulators so far.. I am using one of them and fixing the wire that blows to test  Not sure what to do at this point or where to look for the short!

[A383Wing]

Just for info about the single field regulators.....I had the "solid state" electronic version on my 66.....one day I went out to start the car, and the wire from the ignition switch to the regulator terminal under the hood melted.....all the magic smoke was let out.....I had to perform surgery on the harness under the dash and under the hood to replace the burned up wire.......turns out that something shorted to ground on the regulator, I think the piece of thin cardboard insulator finally wore through from the ignition terminal on the regulator to ground.......

So, not to have this repeated in the future.....I installed an inline fuse holder with a 15a fuse between the regulator and the wire that connects to it......it may not be original, or look pretty, but I don't need a harness fire in the car.

The wire from the ignition switch to the regulator is not fused anywhere in the car harness......

Something to think about for the guys still running single field charging systems

Bryan

[keith88]

Yea I want to put the electronic on but I want to do it after I fix why it blowing, dont want to blow  a electronic one when i put it on.

[A383Wing]

Yea I want to put the electronic on but I want to do it after I fix why it blowing, dont want to blow  a electronic one when i put it on.

Put the electric regulator on and rig up an in line fuse holder with fuse. Install it like mine posted above.....

15a fuses are way cheaper than regulators

Bryan

[keith88]

Could a bad ground to the car or a crappy one cause this?

[birdsandbees]

Have you removed the field wire from the alternator? and tried turning the ignition on?  As others have noted, I suspect your field winding is grounded/shorted out on that new alternator.

[keith88]

Yes done that same results ..although today had some progress and all i did was move the location a 1" over and a new hold down screw Now the wire is not blowing (so far)  but its only charging 12.7 volts lights and Dixie horn or not. But this is an old regulator that might be faulty is one that i was replacing to start with. Have to do some more checking to know for sure.

[keith88]

    A383Wing ....What gauge wire did you use for the inline fuse part?

[A383Wing]

    A383Wing ....What gauge wire did you use for the inline fuse part?

The wire on the fuse part is what came with the fuse holder, found at any auto parts corner store.....I'm thinking it's 14ga .......it's very close to the size of the wire that originally plugs on to the regulator "ign" terminal

[keith88]

Thank you. Not 100% its fixed yet But i gained ground today,once i know for sure than I'm going to change over.

[keith88]

    A383Wing ....What gauge wire did you use for the inline fuse part?

The wire on the fuse part is what came with the fuse holder, found at any auto parts corner store.....I'm thinking it's 14ga .......it's very close to the size of the wire that originally plugs on to the regulator "ign" terminal

What amp fuse ..I see 15 but I have also seen you say 10.

[A383Wing]

Either will work....I have a 15a fuse in it now

[keith88]

Some how I fixed the short.... I have ordered the solid state regulator and fuse like A383 wing showed me ..thank you for that info. Ill be putting it away for the winter in the next few weeks.