Mustang II One Wire Alternator Conversion?

IICrew

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Mar 29, 2020
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As long as you use the appropriate gauge wire from alternator to the battery your fine. The higher amperage will only run on that wire if it's large enough. If this wire is too small it could cause bleedover. I would power any added accessories off relays. Like your headlights. Only use the ignition/oem wiring for a signal to turn on or off the relays.
 
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chrlsful

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Mar 6, 2021
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As long as you use the appropriate gauge wire from alternator to the battery your fine. The higher amperage will only run on that wire if it's large enough. If this wire is too small it could cause bleedover. I would power any added accessories off relays. Like your headlights. Only use the ignition/oem wiring for a signal to turn on or off the relays.
yup, 2 AWG there (w/mega fuse). U remind me, I could use a newer/stronger keyed ign switch or figure how to add these relays U mention. That would save alota rewiring... the ol fuse box is only 5 to 7 slots. Will have CB (its a 4WD 1st gen bronk, not the 1 in sig) 2nd winch battery, that's it beyond it's oem configuration.
Thnx Crew~
 

IICrew

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I am using the stock ignition wire that fed the coil/distributor to trigger all my relays. They in turn power fan/dizzy/radio/coil and gauges. The one ignition wire attaches to one relay and only that one relay. That relay triggers 5 other relays that control the above. No need to upgrade the ignition switch doing it this way. Your actually relieving some stress on the switch.

You really want to minimize what runs through the ignition switch. Just find one wire that's hot with key on. Use it to trigger relays. Being a '70 you may be able to use the dizzy power wire but if it is still set up for points it only has 9 volts. Some relays will work with 9v. Some wont. Just be aware of what your buyng or use a different hot.
 

IICrew

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Mar 29, 2020
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The right tools make wiring so much easier. I hated wiring and half assed it for years. When I got the right connectors and hand tools it was a game changer.

Get a nice wire striper. I used to use a lighter or utility knife. Or god forbid the flimsy crap stripper they sell at autozone. Good Irwin strippers, not the flimsy crap. They make a world of difference.

Dedicated crimper. I have a pair of the ratcheting crimpers that do blue, yellow and red connectors. It makes nice secure connections.

Get good connectors. I like the gel filled heat shrink connectors. They shrink and the gel seals when you apply heat. Avoid the red and yellow ones that come in the cheap wiring repair kits. They are hard as a rock and usually tear. The nice ones are more of a rubber vs the hard plastic of the cheapo ones.

Get some decent wire of different colors. As well as shrink tubing.

Should be able to do that for $150. You can tell me you haven't wasted $150 on other parts or tools. I wont believe it but you can say it.

Lastly a decent meter. You don't need a Snap On Fluk meter but....... I love my MAC meter. and have used several of the attachments I didn't think I ever would. This is like a farm tractor to me. You always buy at least one level up from what you currently think you need. As you get familiar with it you will use more and more of the features on it. If you get the cheapest one you never realize what else you can use it for.

Solder is not a good means for connections. Never solder wires. The joints can break with vibrations. Electrical tape and wire nuts are not for automotive use. I know these things as I have done them with varying degrees of success. The varying is what will frustrate the hell out you. lol
 

LILCBRA

I wish I didn't have all of these balls in the air
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I still hate wiring, but @IICrew ain't lying! Having the right stuff makes a world of difference. I ended up "splurging" on a Fluke meter on Amazon. After having gone through a few different meters of varying degrees, this one will hopefully be the last one I buy. Personally, I just think it's an investment that pays for itself with all of the things I do both in the garage and in the house. This is the one I bought, I don't think it's badly priced....

Amazon product
View: https://www.amazon.com/gp/product/B00HEAMLCO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
 
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MustangIIMatt

Easy there, this ain't a dating site.
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There's what gets used at the shop. Electrical repairs are kind of a specialty of mine. Pro-tip, any of these tools branded "Matco" were made by someone else and can be found cheaper from the company that manufactured them. The big battery cable crimpers and the orange-handled specialty crimpers are from a Chinese company called "Iwiss" that makes damned good knock-offs of other tools.
 
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danielmeyers

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At gas station today I struck up a convo with an old gentleman who had a 2004 Mustang GT. Without even saying anything to him he said "only issues I've had is with the alternator and battery" I started laughing and told him me too. He popped the hood for me and he had a quick disconnect switch to cut the draw when he doesn't drive it. He said a shop guy told him that if he doesn't drive it enough the battery will drain due to all the electrical demand. I've known this from experience though.

And if you worked for ford, you must know that no one takes their car to ford. The cars that are affected are just out of warranty when they start going bad. I've always used mom and pop shops, but after a few times in a row I thought maybe Ford would finally know something and be able to fix it, that's the only reason I went to ford and never again. They just swept the problem under the rug and sold me the whole under warranty speech, without specifying labor wouldn't be included when the alternator goes bad. They also completely disregarded my plea to put in a 2010 3g alternator and said it was out of spec. At least they gave me a complimentary rental before charging me freaking $900 for a basic alternator exchange. I was stuck at work with no options, I had already had the car towed there and they kept under shooting how much it would cost out the door. When it started going bad again I took it back to Ford, she said I would have to pay over $150 or so just to have them look at it, I drove off knowing I could someone write my paper for me https://writemypapers4me.net put that towards a new alt and fix it myself since they continue to play their games.
And it's true - that's almost the only problem. I know that my father has already repaired it a couple of times, or rather not him but his mechanic. I can't say exactly what was included in the repair work, but I think the bearing was changed, a new voltage regulator was bought and the winding was restored, that's all.
The only good thing in this situation is that the repair of the generator is not too difficult.
 

chrlsful

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Mar 6, 2021
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ahma step below post #13. "It works fine." But better would be nice. Have not seen the 'gell filled, cripm-ons (U heatshring too"). Soderin seems quicker than all these steps (I use a battery pin tip one) but may try the nxt gen method now I seen it. BUT, I still dont have the theory, make good use of a tester beyond a bulb/wire (now a probe w/alagator ground & light-in-handel) to test continuity. Dont know an ohm from a watt to a volt...
 

MustangIIMatt

Easy there, this ain't a dating site.
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ahma step below post #13. "It works fine." But better would be nice. Have not seen the 'gell filled, cripm-ons (U heatshring too"). Soderin seems quicker than all these steps (I use a battery pin tip one) but may try the nxt gen method now I seen it. BUT, I still dont have the theory, make good use of a tester beyond a bulb/wire (now a probe w/alagator ground & light-in-handel) to test continuity. Dont know an ohm from a watt to a volt...
Huh?
 
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IICrew

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Yes I use heat shrink too at some points. Interior I just use the connectors. Exterior I add heat shrink. I tend to use heat shrink as strain relief as well.

95% of older car electrical work will be volts. Usually just a matter of if you have voltage at a certain time and place or not. Occasionally Ohms. A test light will fix most problems but a meter is going to really help move to the next level.

Ohms is resistance. aka continuity. Usually you tests ohms with the power off on the circuit. Reading of 0 means wire is conducting electricity. Infinite or anything else but close to 0 is an open. Means electricity is not making it from a to b. Voltage doesn't matter when speaking of ohms. Your just describing how hard it is for the electrons to pass through that section of wire or components. A very long wire or tiny wire can increase resistance. Corroded connections or broken wires will too. Ohms can help you find these problems

Think of the battery as a fish tank. In our case it holds a bunch of water (electrons). This water is under pressure (volts). The battery can fill and discharge itself at a certain rate(amps). Wires are water lines. Bigger lines feed more volumn of water(amps). In our example 15 is the max pressure. We have a fish tank in a car so we really don't want it full. Lets shoot for 12 being the optimal operating pressure of the tank. If we are taking any water out we will drop below 12. So lets add a water pump. It's magical and creates water out of thin air. Our pump needs to be able to pump more than we use. Lets go with 100 amps as the high flow point of our pump and 14.7 as the high pressure. That way if we have the stereo cranking and ac on high. Bright lights on and the wipers cranking away the tank never goes below 12 psi(volts) or 500 amps. We will not use all the accessories all the time so we need a way to control the pump. Lets add a regulator. It can monitor how full the tank is and have the alternator make more or less power/water as needed.

Each electrical item is actually a little water wheel inside. Some things need a giant wheel, like a blower motor. Some things use a tiny wheel, like a marker light. The bigger the wheel the bigger the wire/water hose needed to power the wheel. This is amps. The higher the amperage the more water is needed to keep the item powered. If we have too small of a hose the water wheel will try to spin it's desired speed. It will pull so much water through the hose it gets hot turning to steam and can melt to water line.

Watts is just a measure of work required. It indicates how much volts and amps are required to make something work. It does not tell us what amps or volts. Once we have the wattage we can apply that to the voltage of our chosen system which will tell us what amps will be drawn. This will determine what size wires we need.
 
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LILCBRA

I wish I didn't have all of these balls in the air
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One thing he didn't touch on (and maybe he didn't know - I just found out about this a year or 2 ago....), some of the higher end solderless connectors are surrounded by heat shrink already. :nice:
 
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Enzio

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Yes I use heat shrink too at some points. Interior I just use the connectors. Exterior I add heat shrink. I tend to use heat shrink as strain relief as well.

95% of older car electrical work will be volts. Usually just a matter of if you have voltage at a certain time and place or not. Occasionally Ohms. A test light will fix most problems but a meter is going to really help move to the next level.

Ohms is resistance. aka continuity. Usually you tests ohms with the power off on the circuit. Reading of 0 means wire is conducting electricity. Infinite or anything else but close to 0 is an open. Means electricity is not making it from a to b. Voltage doesn't matter when speaking of ohms. Your just describing how hard it is for the electrons to pass through that section of wire or components. A very long wire or tiny wire can increase resistance. Corroded connections or broken wires will too. Ohms can help you find these problems

Think of the battery as a fish tank. In our case it holds a bunch of water (electrons). This water is under pressure (volts). The battery can fill and discharge itself at a certain rate(amps). Wires are water lines. Bigger lines feed more volumn of water(amps). In our example 15 is the max pressure. We have a fish tank in a car so we really don't want it full. Lets shoot for 12 being the optimal operating pressure of the tank. If we are taking any water out we will drop below 12. So lets add a water pump. It's magical and creates water out of thin air. Our pump needs to be able to pump more than we use. Lets go with 100 amps as the high flow point of our pump and 14.7 as the high pressure. That way if we have the stereo cranking and ac on high. Bright lights on and the wipers cranking away the tank never goes below 12 psi(volts) or 500 amps. We will not use all the accessories all the time so we need a way to control the pump. Lets add a regulator. It can monitor how full the tank is and have the alternator make more or less power/water as needed.

Each electrical item is actually a little water wheel inside. Some things need a giant wheel, like a blower motor. Some things use a tiny wheel, like a marker light. The bigger the wheel the bigger the wire/water hose needed to power the wheel. This is amps. The higher the amperage the more water is needed to keep the item powered. If we have too small of a hose the water wheel will try to spin it's desired speed. It will pull so much water through the hose it gets hot turning to steam and can melt to water line.

Watts is just a measure of work required. It indicates how much volts and amps are required to make something work. It does not tell us what amps or volts. Once we have the wattage we can apply that to the voltage of our chosen system which will tell us what amps will be drawn. This will determine what size wires we need.
Great explanation. It was used by my physics teacher in high school. And he was a car guy too! One typo I think. Instead of 500 amps I think you meant 100. And I think you always use the ohmmeter on a dead circuit otherwise you'll be buying a new fuse for your meter.
 

IICrew

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Mar 29, 2020
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I agree about using an ohm meter on a live circuit. Since I only stayed in a Holiday Inn Express once I cannot claim to know for sure.

That 500 is referring to the battery capacity. It's the cca rating on the battery. Not the alternator output. It has to have more capacity than what the alternator puts out. We also need to have plenty of reserve for starting, sitting with engine off listening to radio and now days the computers staying on to listen for key fobs. Ect.
 
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LILCBRA

I wish I didn't have all of these balls in the air
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I only remember a more rudimentary water analogy that voltage is the amount of water moving and amperage is the force it applies. I knew that Ohms was resistance without an analogy, but all of that has gotten me by well enough. :)
 

IICrew

Mustang Master
Mar 29, 2020
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I have had it described to me that way as well but my brain cannot make it work. If voltage was the amount of water then wire size would depend on voltage. Not amperage. We can put 12 volts on a tiny wire or huge wire. Wire size depends on the amperage we are going to draw. Since amperage can require more wire surface area it has to be volume in the water analogy. Therefore in my brain amperage has to be volume and volts is best represented as pressure. Granted we are comparing apples and oranges so the analogy will have to be flexible but I believe my way fits much better for a beginner.

I have been married for a few decades now so I understand I am probably wrong but.....
 
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