When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I need some advice on redoing some of the wiring coming off the top bolt of my alternator (1984 F150 i6).
In the fist picture below, you'll see the black wire which connects to the top bolt on my alternator. This wire is split into three wires, 2 yellow and 1 black. Both the yellow wires connect to the plug in the second picture, which hooks into the harness that runs into the passenger side firewall. The black wire that splits off the main alternator wire, is split further into two wires, 1 red which connects to the same plug below, and 1 larger gauge red which connects to the starter solenoid.
As you can see, the plug is in need of replacement, and has corrosion on the firewall side of the connection.
I haven't seen plugs like this at the store, I think the guy at Napa said they don't make them anymore. Can I just cut the plug out, and replace all the wiring between the plug and the alternator, splitting and splicing things the same way it is done now?
Yes you can. That spot in the picture above with that black cloth type tape looks like a factory splice. Just do them one at a time so you don't get mixed up. If you replace any wiring, make sure you use thick 10 gauge like the factory did.
I had to do the same you want to do as mine was a mess that the truck came with.
I changed the trucks harness using my parts truck one and then had to match up wires.
I also had to make a adapter / jumper as my harness had a different plug than the ALT I was going to use.
Dave ----
I had to do the same you want to do as mine was a mess that the truck came with.
I changed the trucks harness using my parts truck one and then had to match up wires.
I also had to make a adapter / jumper as my harness had a different plug than the ALT I was going to use.
Dave ----
Make sure you don't simply twist wires together and cover them with electrical tape. I'm surprised Dave mentioned it was probably factory. I saw alot of hacking in the wiring on my truck and @$$umed it was a previous owner that mutilated the wiring. Maybe not...
Use a ratcheting wire crimper and cover all of the connectors with heat shrink. Here's an intro wire crimper kit:
my truck came with messed up ALT wiring but it was charging.
The parts truck harness I used had a different plug to hook to the ALT, parts truck did not have a ALT.
Because I am cheap and the ALT worked and not wanting to cut a good harnes I made 2 jumper wires to fit the harness plug and the ALT.
Dave. ----
Make sure you don't simply twist wires together and cover them with electrical tape. I'm surprised Dave mentioned it was probably factory. I saw alot of hacking in the wiring on my truck and @$$umed it was a previous owner that mutilated the wiring. Maybe not...
Use a ratcheting wire crimper and cover all of the connectors with heat shrink. Here's an intro wire crimper kit:
The factory wiring is full of splices. They used some sort of welder to melt the copper together when they did it. And then that's all they did, wrap cloth tape around it and install it in the harness loom. Works well, but it will corrode once the tape gets old and lets moisture in. I have said it many times and you can see it the more you work on vehicles, they did not build these things to last forever.
Can anyone tell me what the purpose of that adapter/plug is? Does it just make it easier to disconnect and remove parts of the harness?
Are you talking about my adapter plug I made?
Normally there is not one used, the wires from the regulator match the ALT and either plug in or screw on / push on.
That white plug to the right is the harness from the regulator / truck side.
You can see what my ALT connections look like.
No way they would work with out cutting & splicing ends on the trucks harness (that was not going to happen) or swap out a good working ALT (again not going to happen).
So my fix was to make 2 short wires to fit in the white plug with ends to fit where needed on the ALT.
What you dont see in the picture is the 10 ga. black / orange wire that goes from the ALT output to the battery that is part of the trucks harness.
Later if the ALT dose fail I will get the right one so I can remove the 2 "adapter wires" so the white plug will plug into the ALT.
Or depending how I feel upgrade to a 3G ALT but I dont see the need for it on my truck as I am not running anything needing the extra power out put from the ALT.
Dave ----
I believe the above picture is connector C610 in the diagram below. Connects the large yellow wire to power the cab. Connects the small wires to the shunt for the ammeter. Connects the lighgreen/red for the wire to the key-on to bring the alternator online. I am thinking that butt splice looking thing in the picture next to the connector is the shunt.
That is not really an adapter plug.
That is a smaller harness that goes between the trucks main harness and the ALT.
I dont know what the ALT end of that harness looks like on your truck but if it is different than mine that is how FORD switched the wiring, they just pull the needed ALT harness from the bin to match the ALT.
I guess I could try and find that harness that would fit the ALT I have but the setup I have is working so I cant see me changing it out.
Now if you a junk yard with trucks in it you can see if they have a ALT harness that will fit your ALT and swap them around.
Dave ----
I believe the above picture is connector C610 in the diagram below. Connects the large yellow wire to power the cab. Connects the small wires to the shunt for the ammeter. Connects the light green/red for the wire to the key-on to bring the alternator online. I am thinking that butt splice looking thing in the picture next to the connector is the shunt.
Agreed, except for the last bit. The shunt in the diagram is the length of heavy wire between splices S202 and S203. The ammeter is really a voltmeter in disguise. It reads the tiny voltage drop across this length of wire and displays it as amperage. IIRC, the shunt is fairly long and was folded back over itself inside the harness.
S202 is the big ugly splice that was wrapped in tape from the factory. That's exactly how my '84 looked.
S203 is near the starter relay, at the end of fusible link J. It has one big wire (the shunt) and two smaller wires.
Connector C610 is the big round one in your picture. It has one heavy wire and three smaller wires. Note how it is not shown in one location in the diagram, but kinda scattered across the page. See to the right of S202, at both sides of the ammeter, and to the lower right of the alternator.
While you're in there, have you considered converting from a voltmeter to an ammeter? I did the Rocketman conversion a couple of years ago and highly recommend it:
An ammeter is kind of useless for consistent monitoring of the electrical system. It would be easy to miss a slow discharge, such as if the charging system wasn't fully up to snuff. A voltmeter is much more useful, in my over-rated opinion, for catching a charging system fault before it leaves you stranded. I have a diagram of how I rewired my truck for a voltmeter, and eliminated the shunt and C610 in the process. It's on my other computer but I can post it tomorrow if interested.
Agreed, except for the last bit. The shunt in the diagram is the length of heavy wire between splices S202 and S203. The ammeter is really a voltmeter in disguise. It reads the tiny voltage drop across this length of wire and displays it as amperage. IIRC, the shunt is fairly long and was folded back over itself inside the harness.
S202 is the big ugly splice that was wrapped in tape from the factory. That's exactly how my '84 looked.
S203 is near the starter relay, at the end of fusible link J. It has one big wire (the shunt) and two smaller wires.
Connector C610 is the big round one in your picture. It has one heavy wire and three smaller wires. Note how it is not shown in one location in the diagram, but kinda scattered across the page. See to the right of S202, at both sides of the ammeter, and to the lower right of the alternator.
While you're in there, have you considered converting from a voltmeter to an ammeter? I did the Rocketman conversion a couple of years ago and highly recommend it:
An ammeter is kind of useless for consistent monitoring of the electrical system. It would be easy to miss a slow discharge, such as if the charging system wasn't fully up to snuff. A voltmeter is much more useful, in my over-rated opinion, for catching a charging system fault before it leaves you stranded. I have a diagram of how I rewired my truck for a voltmeter, and eliminated the shunt and C610 in the process. It's on my other computer but I can post it tomorrow if interested.
Hmm, maybe later. I'm actually doing this wiring because something is wrong with my charging system, and the wire that attaches to the top bolt of the alternator is toast, all black and melted. I want to get the truck running/charging properly right now.
The ammeter, if that is the actual meter in the dash, doesn't work, so I may come back to this.
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
