Alternator is stuck wide open

[jmdesigns]

Just woke the car up after several years of resting.  Started the new motor for he first time and the alternator has the amp gauge pegged and is squalling the belt. The alternator is new and the second field terminal is grounded. The alternator and the regulator both test ground with a test light off positive of the battery. And I changed the new regulator with another new one and still have the same results. Also the engine harness is new. Any ideas what I can check next?

[nascarxx29]

This is a new engine .And you started it for the first time?..Is it possible that battery is down and alternator is just working harder to get battery back to full charge  Do you know what amp alternator you currently have.You could loosen belt and spin alternator by hand and see if it turns freely .It might be a bearing noise.Making alt hard to turn over and squeel the belt..Are you sure the alt and regulator is good. If none of those .Any possible chance the current pulley arrangement.Might be spinning the alt to fast .Does the amp gauge continue to show high rate of charge for extended periods .And how old is the battery.Just throwing so more possibilities outhere to check and rule out.I had a car were poor pulley alignment caused alt bearing failure.Alt turned over hard and squeeled the belt

[jmdesigns]

The battery is fully charged and new. The alternator is putting out max charge for sure. It even pulls the idle down when you plug the field wire in. The amp gauge reads 20 amp at idle...pegs when you rev the engine and squalls the belt.

[nascarxx29]

 Are you seeing or smelling the battery boiling from excessive charge which is a typical indicator of this overcharge condition.Are the lights brighter than usual .Have any fuses blown .Is alt case getting real hot.I think I would have alt tested or try another .You dont want to do electrical damage to your new wiring harness.If you could get a voltage reading from the battery and its more than 15-16 volts it will confirm somethings not right.If you have a 1 field alt .So you should have the black box voltage regulator that has points and they cant get stuck from sitting.And try another Alt .Leaving the wiring to be checked out

[jmdesigns]

Since I was trying to break in the motor I had no options other than running the car off the battery and a battery charger to at least break in the cam. I replaced the already new regulator with another today and still the same problem.

[nascarxx29]

Have you checked all your connections grounds and power .Is your amp gauge known to be good.How are the connections to it .What Im looking for is anything thats loose or coroded .Will cause high resistance to the wiring

[jmdesigns]

Gauge is good, battery cables new, new ground strap. I just wonder if the new alternator is the problem. Every hear of a bad alternator doing this?

[nascarxx29]

It possible shorted winding in the alternator.Or regulator not well grounded.Will cause overcharging issues

[jmdesigns]

here is pictures of the alt and reg

[Nacho-RT74]

does look REALLY low batt alt.

How many amps is the batt ?

[jmdesigns]

I believe it is 750 cold cranking...new $90 battery

[jmdesigns]

Does it matter which field connection is grounded

[nascarxx29]

The green field wire which comes from the box type regulator you have.From what Ive seen and recall is clocked at 12;00 position upright in back of the alt.

[jmdesigns]

If you look at my first picture I have the field connection @12:00 grounded and the regulator connected to the field connection that is @ 9:00. Is that my problem?

[nascarxx29]

  Personally I havent had that problem.And found that to be the cause.Just my I dont think it matters

[Nacho-RT74]

if you have a double field alt to work like a single field alt doesn't really matter wich one grounds, as far you plug the field on the ungrounded brush. If by mistake you plug the wire on grounded brush, will have an inmediatly short once you put the key in RUN.

Of course there are several ways to ground the brush, one of them is replacing the isolation washer for a metallic one, and just noticed you wired the brush prong with a terminal, plug and wire, so you won't have a short by mistake ever.

I only can say, bad regulator sending full charge like you jump the brush to a constant positive source or low batt, thats all. I don't think is an alternator deal, but who knows 

[nascarxx29]

I see your black box type voltage regulator is gray .Which brand is it out of curiousity as I have had reoccuring defect parts .Does it have points as originals .Or was it the newer electronic type.I dont see alt developing a electrical defect from sitting.I would more suspect the regulator even more so if its the old type with the points.But keep us informed .And what you find out

[jmdesigns]

Both regulators are the point's type. The one I took off was new with a black case. The new one picture is a borg warner from Orielly @ $52 that I just put on. I called an alternator builder and was told to check the alternator fields with nothing plugged into them they should be isolated from ground to be able to tell if there is an alternator problem. Another mechanic told me that that type of alternator would not work with a point's type regulator.

[Nacho-RT74]

of course won't work IF both brushes are isolated, but being you are grounding one of them is teh same effect than earliers ones.

did you told to the mechanic you grounded one of the brushes ?

[nascarxx29]

The 2 field alternator. Typically uses a flat type regulator .But as you grounded 1 of those 2 fields .Its now a single field alt.And that the type of regulator is right for the 1 field.That your using

[68 RT]

You need to get a solid state regulator. I was having the same problems with my points type reg. There is a thread on this somewhere. You can get solid state regs that look stock off ebay, can't remember the seller. I think year one has them too. This cured my problem. Look at your regulator bet the points are welded shut. Good Luck!

[nascarxx29]

Did at another time .This particular alt and regulator and engine wiring harness you started the car up on recently work fine before .Or you just experienced this problem at this first start up.Ive gotten repo harnesses in earlier days where I had to make a fix.As the wires were in the connector plug in the wrong color order etc.If you alt tests good and same for regulator .And grounds are all ok .I start suspecting the wiring and check it from the firewall connector to bulkhead and evalute it .Testing 1 wire at a time for continunity and crossed or pinched wires

[nascarxx29]

You need to get a solid state regulator. I was having the same problems with my points type reg. There is a thread on this somewhere. You can get solid state regs that look stock off ebay, can't remember the seller. I think year one has them too. This cured my problem. Look at your regulator bet the points are welded shut. Good Luck!

Thats been my experience the point types are trouble prone.And a electronic one was available . I supected stuck points but hes on his second regulator.And these electronic parts you cant usually return.

Re: Alternator is stuck wide open
« Reply #16 on: Today at 10:06:23 AM » Quote Modify 

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I see your black box type voltage regulator is gray .Which brand is it out of curiousity as I have had reoccuring defect parts .Does it have points as originals .Or was it the newer electronic type.I dont see alt developing a electrical defect from sitting.I would more suspect the regulator even more so if its the old type with the points.But keep us informed .And what you find out

[jmdesigns]

Wish I still had the single field alternator to put back on.
I will check the alternator tonight according to the rebuilder and see that both fields are isolated from ground which will prove the alternator as good or bad if not isolated. I will let everyone know how this turns out.

[jmdesigns]

I check the alternator and both fields are not shorted. I have read several post here and have tried all suggestions. I am going to take the alternator and regulator to the re-builder and he said he will be able to tell me what is going on, I will post his results tomorrow. I just hate not being able to fix a problem myself. I have brought this car from a basket case with half the parts missing to done minus interior in 2-1/2 months. Shown is what I started with and where I am at today, all myself minus the windshield install and exhaust.