Alternator wiring / seloniod / MSD box

What is the proper wiring for the alternator harness as far as the ground goes. Where did Ford originally place it? I grounded mine to the negative side of the selonoid (where the starter wire goes) but i was thinking what happens if i crank the motor over? Wouldnt that terminal supply 12 volts to it.

I currently have my MSD Digital Box, Alternator Harness, Electric Fan, and Starter Cable mounted to this post. I never had the car started yet, not ready. I have turned the key and had heard the selonoid ringing the way its supposed to. No burned wires.

So before i do anything lets hear some suggestions.

What is the proper and correct way to wire and ground placement. Especially for the alternator wire.

No post on the selonoid are grounds.

The negative cable from the battery is grounded in two locations if you have an original style cable. If you do, there is a small metal tab crimped to the cable about 1/3 of the way down the cable. It attaches to the bottom screw of the regulator using a toothed washer. The end of the cable attaches to a threaded hole at the front right corner of the block with a bolt and a toothed washer. This is the location I used to ground the MSD 6AL. Is the alternator wire you are referring to an 8 gauge black wire with an orange stripe? Does the car have factory gauges? If so the wire attaches to a single post terminal block about 1 inch forward of the regulator. Exactly how all the wiring is routed and attached varies with year, date of production, and options such as convenience group, heated rear glass, gauges, and convertible top. Have you looked at the wiring diagram on this site? Good Luck, Chuck

Ya its kinda hard for me to read. No the ground wire from the alternator is pretty thin no other markings. I dont have the style battery cable you do. I have all reproduction wiring for alternator and battery. 73 Mach 1, have gaigrs but not hooked up. My car didnt come with them. Originally. I believe i do have convience package.


The concouse style bat cables i got come with the pos neg and starter cable

The solenoid is grounded to the body by it's screws. As oldmountainfarm pointed out there is no ground wire going to it. If you can, how about posting a picture of what you have. REMEMBER!!!! DO NOT CONNECT THE NEGATIVE OF THE BATTERY UNTIL YOU VERIFY WITH A TESTER THAT THERE IS NO VOLTAGE!!!! or have an extinguisher at the ready.

REMEMBER!!!! DO NOT CONNECT THE NEGATIVE OF THE BATTERY UNTIL YOU VERIFY WITH A TESTER THAT THERE IS NO VOLTAGE!!!! or have an extinguisher at the ready.

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YEP, Great Advice.

mike

Ya its kinda hard for me to read. No the ground wire from the alternator is pretty thin no other markings. I dont have the style battery cable you do. I have all reproduction wiring for alternator and battery. 73 Mach 1, have gaigrs but not hooked up. My car didnt come with them. Originally. I believe i do have convience package.


The concouse style bat cables i got come with the pos neg and starter cable

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The alternator grounds when it is bolted to the block. The alt. should have 3 wires, Black with orange stripe, White with black stripe, and Orange with a light blue stripe. At the regulator, depending on the harness you have, Orange/light blue stripe, Light green/red, and Yellow with white dashed line. There are at least two or three different configurations for 1973. Any part numbers on the packages? If the battery cables are concours the negative cable should have the ground tab and be marked Motorcraft ( not Autolite). Pictures of the harness would help. Chuck

Well doesnt the neg battery cable go in the post on the right? With the battery hooked up, the ground wire coming off of my alternator harness when i put it on this post, it completes the circuit allowing power to the rest of the car, When i did this the wipers, lights, anything in the on position turned on.

The solenoid is grounded to the body by it's screws. As oldmountainfarm pointed out there is no ground wire going to it. If you can, how about posting a picture of what you have. REMEMBER!!!! DO NOT CONNECT THE NEGATIVE OF THE BATTERY UNTIL YOU VERIFY WITH A TESTER THAT THERE IS NO VOLTAGE!!!! or have an extinguisher at the ready.

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Do you mean alternator bracket? Not the alternator electrical connections.

No not the bracket. I have a ground wire coming off of the alternator harness that plugs into the voltage regulator. Ill provide pics asap

I would like to see the pic's. I'm still cleaning up some issues with my 71. I saw a shaved mark on the original harness that has me curious .... was it cut for some reason? I'm running an MSD also with stock tach. But My issue is I need to replace the alternator...and it has a two prong recepticle (received on the last attempt) and the wiring is 1 single plug.

Well doesnt the neg battery cable go in the post on the right? With the battery hooked up, the ground wire coming off of my alternator harness when i put it on this post, it completes the circuit allowing power to the rest of the car, When i did this the wipers, lights, anything in the on position turned on.

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My Gawd, no! The starter cable goes to the big post on the right. The negative battery cable goes to the alternator and the block.

There's another largish wire that goes from the forward large post to the alternator that carries voltage from the alt to the battery.

Please consult the manual or other wiring diagrams before you start a fire by mis-connecting the battery!

Okay the diagram is helpful, but I would like to see any pic's of your harness' I'm running a MSD and a single plug or prong (*some had two prong connectors) with the brown/light brwn stripe ( *single wire plug) and the tan running to the post. I'll double check.

Anybody running an MSD?

Another question, NAPA cant seem to get the right alternator...last one they gave me was for a late 70's Bronco or Econoline van

Ill try to get some pics of mine up.

Ill try to get some pics of mine up.

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That would be great Mikepasquale. What year model or "model" alternator are you running?

I had similar issues with my car, couldn't figure out the wiring for the alternator. Ended up just buying a chrome one-wire alternator, just one wire strait to the battery, problem solved. Works fine with my MSD box.

Just thought I'd throw that idea out there.

73 Mach, MSD 6A Digital, THe alternator was a reman 60 or 61 amp from Napa. My issue was i couldnt get power to the car but i figured it out when i realized i had alot of the wiring screwed up. I have feeding 12v into a ground. (I was grounding to the starter cable side of the selonoid. LOL ya laugh. After i hooked everything up correctly i have complete power to the car, and MSD box. My MSD has a LED indicator on it that turns Red when the car is in KEY ON position which it does. I have yet to start the car. but so far everything seems to be working properly. I have starter cable disconnected as of right noe until im ready but if you turn the key to start, you get the usual selonoid ring. Im itchin to start it. Few more weeks and should be good to go. Waiting on CJ pony Parts. They never have my stuff in stock. 8 items on back order.

yeah before i go crazy i'm going to check the wiring set up