66 Mustang Electrical Help???

Hi All,
My brother has a 66 Mustang and it is pretty much completely restored except one of the most important things. At least that is what I told him after he
spent big bucks on the resto. Anyways, he is having an electrical nightmare. He replaced the solenoid, and alternator. The starter is good and the car runs good after started. When he puts the negative cable on the battery he says it is arching a whole lot (described it as if he were welding almost) and cannot figure out what is going on. He has a voltmeter hooked up that does not work. I told him to completely remove the volt meter wires from end to end, because that is usually one of the main problems because they carry allot of juice. He also said when he tests the positive side of the starter with a meter that he is getting resistance (should he be getting a grounding type of resistance from the positive side). I think he was using an ammeter or ohm meter. I further told him it could be anywhere in the ignition wiring. Is there something that I have missed or is there something that is typically wrong with that year Mustang. I know the older Mustangs typically had electrical and overheating problems, but the three Mustangs I have owned 68, 69, and 71, didn't really have any significant problems. Any advice would be greatly appreciated. He is getting pretty frustrated with his new project and really want to start enjoying his Mustang...
Thanks again John
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it is obvious he does not know what he is doing. first thing, the starter will show resistence. if it does not ,it is no good. the first thing he should get is a service manual and then a wiring diagram. there is a troubleshooting section in the manual that will solve 99% of all problems
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That spark when putting on the negative cable means that somewhere something is drawing a lot of current. It sounds like a major ground. I would look at the voltmeter and it's wiring first.
max-income
Every day is a good day- it's just that some are better than others.
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John wrote:

If the battery cable arcs when he hooks the battery up something is drawing current, he needs to figure out what that is or he will run the battery down every time he leaves it sit. With an older car there should be zero current draw with the key off unless you have the door open (dome light)
good luck
nate
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Car batteries can be charged "backwards" If the battery was completely drained in storage and he happened to accidentally reverse the polarity when he charged the battery... Pos may now be physical ground.

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Thanks to all for the input you provided. It turns out it was the voltage regulator. The reason he didn't replace it with the other things was because he was told that when he bought the car it had just been replaced. Could have just been a bad one. Everything seems to be working for now. We will see how the next few days go and see if there is anything else wrong with the electrical system.
John

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You partially solved your problem but still need to attend to the battery.
Typical FoMoCo generator-regulator ailment due to a bad generator regulator. Those regulators were prone to go bad and had three stage electro-mechanical relays in design.
DO NOT operate the vehicle without either replacing the battery or recover it by discharging it and correct recharging.
The battery if it is not old may be recovered by completely discharging it SLOWLY by leaving the headlights on until the lights are no longer illuminated.
Then recharge the battery SLOWLY connected with correct polarity to a constant current charger. Most constant current chargers have a heavy transformer. Constant voltage chargers have a light weight transformer and normally sold today at many discount stores.

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I had a '66 Mustang years ago (289?) and it used to "eat" regulators. I think this was the main electrical problem with these cars. Also, I got quite good at changing water pumps :-) might a well tell your brother to be prepared for this!
BobP

restored
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wrote:

If it's a 289, with a manual trans, then also watch your rearend.. my father had a 66 289, and put about 5 rear ends in it.. the 289 has tons of torque and would shear the rearend gears.. he also broke a universal on it.. broke it clear in half..
BUT.. that car would lift the front end a few inches off the ground when he'd pop the clutch.
Chuck Burns
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Well the car is long gone now, but you're right about the power!
BobP

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This is a multi-part message in MIME format. --------------000306020809000805020400 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit
I had the same problem with my '69 Torino. It seems I was putting a new regulator in every six months. I used to use it to jump cars a lot (when we ran them around the field before a trip to the yard) with it, and I think that had something to do with the problems I had. Even so, I would still count on changing regulators often (and water pumps too).
-Rob
Bob P wrote:

</pre> <blockquote type="cite"> <pre wrap="">John wrote: </pre> <blockquote type="cite"> <pre wrap="">Hi All,
My brother has a 66 Mustang and it is pretty much completely </pre> </blockquote> </blockquote> </blockquote> </blockquote> <pre wrap=""><!---->restored </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">except </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">one of the most important things. At least that is what I told him </pre> </blockquote> </blockquote> <pre wrap="">after he </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">spent big bucks on the resto. Anyways, he is having an electrical nightmare. He replaced the solenoid, and alternator. The starter </pre> </blockquote> </blockquote> </blockquote> </blockquote> <pre wrap=""><!---->is </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">good </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">and the car runs good after started. When he puts the negative </pre> </blockquote> </blockquote> </blockquote> </blockquote> <pre wrap=""><!---->cable </pre> <blockquote type="cite"> <pre wrap="">on </pre> <blockquote type="cite"> <pre wrap="">the </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">battery he says it is arching a whole lot (described it as if he </pre> </blockquote> </blockquote> </blockquote> </blockquote> <pre wrap=""><!---->were </pre> <blockquote type="cite"> <blockquote type="cite"> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">welding almost) and cannot figure out what is going on. He has a </pre> </blockquote> </blockquote> <pre wrap="">voltmeter </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">hooked up that does not work. I told him to completely remove the </pre> </blockquote> </blockquote> </blockquote> <pre wrap="">volt </pre> <blockquote type="cite"> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">meter wires from end to end, because that is usually one of the main problems because they carry allot of juice. He also said when he </pre> </blockquote> </blockquote> </blockquote> <pre wrap="">tests </pre> <blockquote type="cite"> <pre wrap="">the </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">positive side of the starter with a meter that he is getting </pre> </blockquote> </blockquote> </blockquote> <pre wrap="">resistance </pre> <blockquote type="cite"> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">(should he be getting a grounding type of resistance from the </pre> </blockquote> </blockquote> </blockquote> </blockquote> <pre wrap=""><!---->positive </pre> <blockquote type="cite"> <blockquote type="cite"> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">side). I think he was using an ammeter or ohm meter. I further </pre> </blockquote> </blockquote> </blockquote> </blockquote> <pre wrap=""><!---->told </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">him it </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">could be anywhere in the ignition wiring. Is there something that I </pre> </blockquote> </blockquote> <pre wrap="">have </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">missed or is there something that is typically wrong with that year </pre> </blockquote> </blockquote> <pre wrap="">Mustang. </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">I know the older Mustangs typically had electrical and overheating </pre> </blockquote> </blockquote> <pre wrap="">problems, </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">but the three Mustangs I have owned 68, 69, and 71, didn't really </pre> </blockquote> </blockquote> </blockquote> </blockquote> <pre wrap=""><!---->have </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">any </pre> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">significant problems. Any advice would be greatly appreciated. He </pre> </blockquote> </blockquote> </blockquote> </blockquote> <pre wrap=""><!---->is </pre> <blockquote type="cite"> <blockquote type="cite"> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">getting pretty frustrated with his new project and really want to </pre> </blockquote> </blockquote> </blockquote> <pre wrap="">start </pre> <blockquote type="cite"> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">enjoying his Mustang...
Thanks again John </pre> </blockquote> <pre wrap="">If the battery cable arcs when he hooks the battery up something is drawing current, he needs to figure out what that is or he will run </pre> </blockquote> </blockquote> </blockquote> <pre wrap=""><!---->the </pre> <blockquote type="cite"> <blockquote type="cite"> <blockquote type="cite"> <pre wrap="">battery down every time he leaves it sit. With an older car there should be zero current draw with the key off unless you have the door open (dome light)
good luck
nate </pre> </blockquote> <pre wrap=""> </pre> </blockquote> <pre wrap=""> </pre> </blockquote> <pre wrap=""><!---->
</pre> </blockquote> </body> </html>
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If you are not set on keeping with the "relay-type" regulators you may want to consider switching to an electronic regulator. An Auto-Electric supplier would have the regulator and conversion wiring harness in stock. Directions are simple and only takes about 20 minutes. Should run around $30 or less for parts. I have even converted GM vehicles to the ford regulator with ease. Safer and one less thing to go wrong....

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Caution "to consider switching to an electronic regulator" you are limited to converting to a alternator if you have a generator. I have never seen a Ford generator electronic regulator. If you have an alternator "consider switching to an electronic regulator" and rewire conversion for a electronic regulator.
Or another alternative is to convert to a alternator with a integral regulator and rewire.
Be careful of the alternators clock position for enough wire. If confused, you can get a Xerox copy of a microfiche wiring diagram for a few years newer Mustang that came stock with a alternator for a nominal fee at a public library. Or follow a conversion kit instructions.

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year
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door
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Next time he changes his alternator, tell himmto consider a single wire alternator with a built-in regulator... it will save him alot of grief in the long run. I've had good success with my Powermaster 140 Amp unit.
--
Pat Ford - Columbus, Georgia
Fully Restored and Modified 1966 Mustang Coupe
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How much did you pay for the Powermaster? Where'd you pick it up?
Scott Williams '66 HCS

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It was about $250.00 from Mustangs Unlimited. A big chunk of cash, but necessary for all the new technology I have in the car. 60 amp units just don't cut it for those of us who have put in A/C, electric fans, radios, CD players, amps, and other gizmos to help us run fast, loose, and comfortable.

--
Pat Ford - Columbus, Georgia
Fully Restored and Modified 1966 Mustang Coupe
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That is pricey. Do you know if there's a "middle of the road" alternator out there. Not as wimpy as stock but not as much as the Powermaster? Like a 100 amp alt?
Scott Williams '66 HCS

CD
comfortable.
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"Scott Williams" wrote:

out there. Not as wimpy as stock but not as much as the Powermaster? Like a 100 amp alt?

You can get 100 amps units for much less, about $120 - $165 depending on the type of finish you want on the case. I've included a link to one place that popped up on a google search. I'd check prices at other places too. http://www.streetortrack.com/powermaster.asp
--
Pat Ford - Columbus, Georgia
Fully Restored and Modified 1966 Mustang Coupe
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