Wednesday, April 5, 2017

1979 Ford Mustang 1G to 3G Alternator Conversion

1979 Ford Mustang 1G to 3G Alternator Conversion
These are the parts you will need. You will also need tools to remove your existing alternator. I have a custom pulley setup, so I will be modifying things. Most people will not have to make a custom length power cable. I am not most people so I will be modifying and making my own additional cable piece to go to my power post under the hood. My setup is not the norm due to the battery being relocated to the trunk. Late Model Restoration had all the parts I required. I did not order their normal kit but they assisted me in piecing it together because I had requested a Polished Alternator. The alternator pictured is PA Performance Lifetime Warranty 130 Amp Alternator.

Below to left is the PA Performance External Voltage Regulator replacement part that allows you to still use your factory harness, however you still need an additional power cable to the alternator that needs to be installed with your existing one else you may have an electrical fire. The 130 amp alternator that is pictured is over double the amperage of what this car was designed for, however it is required due the the high performance ignition system installed and the large electric fan that is installed.

The additional power cable that is pictured is offered from PA performance and is 4 gauge speaker wire with an inline Littlefuse 200 amp fuse block and fuse. You could probably build this cheaper than what is charged pending on length you buy. The short cable provided was too short to get where I wanted to mount the fuse block, so I made a new cable with 4 gauge cable purchased from West Marine. They have high end tin coated marine grade cable that is also UV resistant. They also sell heavy duty lugs which I used on the ends.


After disconnecting the battery begin by removing the old alternator, which by the way was chrome and bought off ebay. When it failed I had it rebuilt by a shop in Dubuque, IA. Now when it was in Dubuque I was informed that this was a 55 Amp alternator, which was news to me because I was informed it was a 100 amp when it was bought. Never trust Ebay sellers. The alternator shop was able to order components that would get it up to 70 amps, but regardless it wasn't enough for what I was pulling after reinstallation. Hence, the 1G to 3G upgrade.

Pull things apart with care. Also helpful tip when you have polished engine parts it is handy to use a plastic coated ratchet this will help you to prevent scratching anything. Harbor Freight has plenty of ratchets that are plastic coated. Now in the picture to the right you see the shelf that I had frabricated for mounting the MSD Ignition System and the Fan Thermal controller to. This is where I intend to mout the Fuse block.

I disconnect all connections here to give myself some space to work without worries.

Here I am figuring out placement and marking where I want to drill out my holes at.

I will be using these stainless steel mounting screws, but I will be grinding the sharp tips off. Now if your asking why I am doing this then let me enlighten you. Under that shelf is where I am shoving all my excessive wiring for the car. Grinding the tips off the screws will help to prevent me from damaging any of that wiring when I push the wiring underneath.

Once I have predrilled my holes I can easily and accurately screw in my fuse block exactly where I want it. Take care not to overtighten though you don't want to brake your fuse block housing.

Now here you can see the old school external voltage regulator as you can see it is mounted to the left side of the engine compartment. This will get replaced with the adapter from PA Performance.

Here you can see that the PA performance harness adapter looks just like the external voltage regulator.


Now below is a Harbor Freight Hydraulic Crimper and I must say this tool is awesome I have used on automotive and home electrical applications and it works fantastically. I used this to make the new cable that will reach the power post mounted to the strut tower on the passenger side of the car. Most of my wire harness in 79 was mounted to the starter solenoid and I just couldn't have that anymore on my car, especially after I converted to a high torque mini starter on the car, so every harness power related goes onto the post including the large battery feed cable that runs through the firewall all the way to the trunk of the car.

Oh I am sure my brother will have comments about my hair thinning lol..

You can see here that hydraulic crimper does amazingly tight crimps, but I take an additional sealing precaution and shrink tube the end connector.

Here you can see how things look now that the new additional power cable is routed and the fuse block is mounted.

Now these rubber boots can also be purchased at West Marine and these help to prevent you from accidentally arcing out on the power post. Well worth the few bucks to prevent an accident. When battery is hooked up this hot always take care when dealing with electrical. 

Now next step after the 1G alternator is removed from the car is to prep the new 3G 130 Amp alternator for installation. Removal is self explanatory, relieve tension on the serpentine belt then remove the belt. From there unbolt the alternator.

Too the right you can see the new 3G alternator with built in voltage regulator. Now that alternator came with a crimp end on for attaching to the ignition wire that is forwarded through the alternator harness. Yeah crimping is kind of a half assed way of doing things and it leaves the electrical exposed to the elements. Copper over enough time with corrode and deteriorate, so I will be soldering that wire and shrink tubing the connection.

Here you can see I disconnected the alternator wire harness under the hood to make things a little easier. White wire is the Stater on this and is plugged in. The Yellow wire goes to the battery positive post which is the feed wire back to the battery or battery positive post. The Green wire with stripe goes to your ignition which happens to be orange on this harness. I have cut the end off here and stripped then twisted the wires together... ***CORRECTION*** Do Not do this on a 1979 Mustang... Green Wire with Stripe doesn't work on the Red / orange wire on your original alternator harness as the instructions provided from PA will tell you. You need a constant close to 12v or 12v at key on. SKIP down and I will show Pics..

Do not do this part. 

Do not do this part

Here I am heating up solder flux to put on the wire ends this helps the solder suck into the joint when applied.

Here you can see a perfect solder joint that even NASA could be happy about.
After the soldering is completed wipe off any excessive flux Then cover the joint with the shrink tubing that you put on the wire before twisting together the two wires.


After shrink tube has been shrunk down carefully with a lighter. You can tidy things up a little more by wrapping with electrical tape. A little tip when using electrical tape never stretch the end part otherwise the tape will unravel. The correct way to finish the end portion is to cut with a scissors and wrap without tension for last part of the wrap.

Next step is to install the alternator into the car. Now your alternator came with a little baggy and inside was a mounting bolt. This will be needed because the top mounting hole went to a different size bolt.

Another issue you will need to fix is the mounting bracket for top mounting point. Modification may be required. Mine required modification because the hole on the bracket piece was not centered with mounting point on alternator, so I had to file out the hole to make it work.

Lots and lots of filing and test fitting lol

Once in finally you can celebrate.

To cover all bases the original Stater wire White and black will no longer be used the original ignition wire on the alternator harness will be soldered to the green and purple wire for the alternator regulator plug. The Yellow regulator plug wire goes to the battery positive terminal on the back of the alternator along with the large black power wire from original harness and the new 4 gauge power feed wire. The White and black stripe wire on regulator plug goes connects into the alternator.

You should be good to go now.  

Sorry for the delay since last post. Finances and free time have been difficult lately. 

UPDATES ON THIS POSTING FOLLOWS. I have seen many people having the issue that occurred to me where the alternator wasn't putting out 12 volt and was running down the battery. Reason is that the internal regulator needs power to perform it's function. Just trying to make the Hotrod Power Tour with my brother at this point, so nothing fancy. You need a constant 12 volts or near when the key is turned on, so I tapped into the electric choke to perform this function. Added wire end shown to protect against contacting anything. Green wire with stripe now connects to same power feed as electric choke. This provides needed power to the internal regulator, so that it can perform it's function. 

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