'86 Ranger Alternator Wiring

[85_Ranger4x4]

Needing to wire up a alternator. It has a green and a yellow wire going into the plug in. It has two heavy black wires and one tiny white wire going into the case.

Anyone know what does what? The green and yellow wires I assume activate it but I don't know which is hot and if the other is ground or what.

And then the two charging wires, IIRC they were connected together back when this thing was in the truck... which doesn't make a ton of sense either.

And the little white wire I don't think was even hooked up.

 

[adsm08]

86 or 85, I think it makes a difference.

 

[85_Ranger4x4]

It is a fairly new one that used to be in my '85 with the 2.8 and phase one of my 302 before the Explorer FEAD went in, someone before me converted my truck to be internally regulated. When I got a new alternator I had to get one for an '86, which is what this one is. From the factory '85's are externally regulated.

 

[Mark_88]

Almost sounds like the one I have in my 96...can you take a picture of what you have? I still have the wiring harness from the 2.0 carbed engine but that one had two plugs on the alternator...one had three wires and the other had two.

 

[85_Ranger4x4]

Best picture I have right off hand.

 

[Mark_88]

OK, that is the same as the one I had on the 88 2.0/2.3...I have the wiring harness with the plugs on it and was holding it this afternoon but found what I was looking for.

I can take a picture of the wiring harness tomorrow and pop it up here...or send it via pm if that works. There should be two plugs on this unit...one with three wires and one with two...is that what you have?

 

[adsm08]

Ok, that's why I was asking.

Orange/blue, Black/orange, and Yellow/white are all hot all the time. The two white/black wires are two ends of the same wire, green/red is key switched power, and the unit is case grounded.

 

[85_Ranger4x4]

OK, that is the same as the one I had on the 88 2.0/2.3...I have the wiring harness with the plugs on it and was holding it this afternoon but found what I was looking for.

I can take a picture of the wiring harness tomorrow and pop it up here...or send it via pm if that works. There should be two plugs on this unit...one with three wires and one with two...is that what you have?

The side closest to the camera is a plug connector. The one on the far side with the two black wires and a white wire kinda looks like a connector but doesn't seem to want to unplug.

There is only one white wire it is looping around and going behind the case in the pic, but there are two black wires coming out of the unit. They both do the same thing?

As you can tell this thing isn't going into an RBV so I pretty much have a clean slate as far as wiring goes...

 

[Mark_88]

I just got a couple of pics of the plugs...need to transfer them over to my other phone via bluetooth before I can upload them...pita...but it's the only way I can do it if I forget my camera phone...lol

Anyway...the two black/orange stripe wires are joined into a single black/orange wire so, yes, they are one wire (I guess it has to do with AC to DC or something)...and the plug also has a singe white with black stripe wire...the other plug has a green and a yellow wire but I couldn't trace them beyond that harness because they go off into the firewall connectors...

I just hope I had enough light to show the colours of the wires...

 

[adsm08]

There is only one white wire it is looping around and going behind the case in the pic, but there are two black wires coming out of the unit. They both do the same thing?

I'll have to get the book back out when I get home.

I was looking at a 91 diagram, which might not match the 86 correctly. I have an 88 book at home, somewhere. The wife keeps packing things I still need out.

 

[Mark_88]

The plug images...not too clear...but should give you an idea if these will fit...

OK...viewable but not good quality...lol

 

[85_Ranger4x4]

After a pretty extensive detour on the project I am getting back to how I want to wire the thing. It hit me today; "hey, I thought we had wiring diagrams somewhere in the tech library?" Sure enough we do!

Found this and it pretty much confirms what everybody here was saying. The two black heavy wires are both coming out of the alt and go to the battery post on the starter relay (or in my case starter switch) Yellow wire going to the alt connector needs constant battery so it goes to the starter relay/switch too. Green is hot with the key. Don't know what white really does yet, I don't remember what if anything it did when alternator was in the truck.

When I swapped this alternator for the Explorer one in my Ranger I swapped connectors for the Explorer one because they were in different locations and since it charges they must do the same thing per color. That was '86 to '97, not that I wouldn't put it past Ford but is unlikely they changed it for a year or two in the middle.

 

[Mark_88]

Looks like my images disappeared...lol...must have cleared the wrong ones out...if yours is working now then you probably don't need mine...especially since I didn't show much more than the colour of the wires...

I can repost them if you need...might still be on my attachment list but I also have them on PB...

Added the wiring for 96 alternator and another shot of the white/bl wire...maybe relay...

 

[85_Ranger4x4]

No wiring done so it isn't working yet. Do you have that alternator yet? I am wondering where that white wire is supposed to go back in the alt at or what it does.

 

[Mark_88]

Not yet, been changing plugs...I just noticed that the wiring diagram you have is for the 91, but the actual wiring is from a 88 2.0 or earlier that might be more relevant. Is that alternator off a 91 4.0? If so, it might be very similar but not the same...

The 1991 diagram shows the white wire (with black stripe) going from one point on the body of the alternator to another point on the body. The wire connectors that you are using there shows a much longer white wire than what my 96 has for the same purpose. It would be nice if they could have shown wire thickness in these diagrams because I've often been thrown off by looking for a 14 or 16 gauge wire only to find out it is a 20 or 22 gauge...the white wire on my 96 appears to be 18 or higher...but my memory needs refreshing.

I will get pics of the 96 white wire setup that shows how it returns to the alternator on another connector and see if I can pull the wire harness from the 88 2.0 and not just the connectors.

I can probably even send you the connectors if I didn't already cut them off the harness...yours looks like they have been chewed to the rubber...

I will be outside later this morning if it isn't raining and I can get you some pics...gotta go find my right winter work boot out there so it will be incentive to do both...

UPDATE: So...I found the wire harness and traced the white/bl wire...goes all the way to the passenger side fender and dead ends in the connector shown in the image below. The black/orange wire is the main power that goes back to a connector that feeds through the firewall to the staring ciruit. I also got a shot of the 96 wiring on the alternator and you can see the white wire loops as shown in the 1991 4.0 diagram (or maybe 1992).

So...I have no idea what that white/bl wire is connected too...but it has several wires so it may be activated by that connector...maybe a relay of sorts that allows the altermator to charge or stop charging...like an on/off switch.

I put the 96 wire image in the post above this...only lets me do 4 images per post...