85HPP 3G alternator install

[1987cp]

It's just safer to disconnect the solenoid end of the old charge wires when installing a new one, as that will eliminate any potential danger with very little effort. Plus, you'll have the nut off that stud anyway when you go to install the new charge wire, so should take all of 10 seconds to disconnect the old one (maybe a minute or two if you have to walk around to the driver's door to make sure of which terminal is for the headlights). In short, for less effort than it takes to type another couple of posts about it, you can eliminate any reason to worry, with no tape required.

[1990LTD]

Gotta actually disconnect them from the solenoid, even if they're snipped on the other end and not goin' anywhere?

I figured fishing the wires out would come in to this at some point

[1987cp]

The best way to get rid of your old charge wire is to remove the whole alternator/headlight harness and fish out everything you don't need. Short of that, as long as you disconnect the old charge wires at the solenoid (it'll be whatever goes toward the front of the car that doesn't disable the headlights!), there's no need to worry about taping them or anything.

I'd actually suggest leaving the old circuitry as intact as possible, just so it can be reused if someone really wants to - the only thing I'd actually cut would be the green wire, since everything else will be self-contained in your new harness.

[1990LTD]

Oh, okay, so I can just get rid of that entire rectangular plug all together? I nix those, run green on new plug to green on car, run b/w to the stator plug, and the last one to the charge post.

Am I correct in assuming that since I'm replacing the stator wire and charge wire that I can just snip the old ones and have them doing nothing? Not just hanging there where I cut it of course, but I mean I don't need those anymore, right? So the only wire from the old setup that's doing anything is the green running to the lamp circuit, yeah?


How does one take care of the wires so they're not just hanging there? I am not opposed to lots of electrical tape on the end since I don't think it really matters what happens to the wires since they're not going to be running to anything as they will be snipped on both ends.

Please correct me if I'm mistaken about ANY of this!!!!

[gadget73]

Small wire is white/black wire to feed the stator. Its the same wire that comes out of the small plug. It needs to go to that smallish connector on the side of the 3g unit.

[1990LTD]

Last question (I hope) - on the rectangular plug going to the original alternator there are three wires, I know I'm supposed to just disregard the two fat ones but what about the third smaller wire?

[91waggin]

One thing I don't know is where the yellow wire from the regulator goes to in a factory-stock harness. The old install on my car just had it going to the charging post, and that worked fine.

This is the voltage sense wire for the regulator. On 2g alternators it runs all the way around to the starter relay (perhaps to take the voltage drop of those dinky charge wires into account). If you have a big fat battery cable running off the charging stud, there ought to be no voltage drop due to resistance between the charging stud and the positive battery post, so you can attach that yellow wire to the charging stud without a problem.

[1987cp]

Heat shrink tubing is lots better because it'll actually seal against the wire and stay nice, but electrical tape can be better than nothing so long as you don't mind rewrapping it every couple of years.

The most convenient way to seal the butt joint is with a special automotive butt connector where the connector's insulation itself is made of a heat-shrink material. Around here they can often be found at auto parts stores, but I don't usually spring for them because they're pricier than the regular plastic-insulated variety and I'm cheap, plus I'm pretty well stocked up on heat shrink tube for joints I actually care about. Anyway, they look kind of like this, and all you have to do it crimp it good and hit it with a lighter for a few seconds to seal it up.

[1990LTD]

Ok I just built myself a little tester and I can connect wires just fine. I don't know why I didn't have this figured out a million years ago. Should I electrical tape the whole of the connector to finish it off?

[1990LTD]

gotcha. how far in should the bare wire be going? where exactly along the length of the connector do i crush/crimp? just on either end?

[Bowman85merc]

a butt connector is what you said you have a pile of (post #29) if thats what your talking about you need to strip back about a 1/4" of wire, stick wire in connector upto the insulation and crimp that end then do the same on the other side with the other wire. you've now connected 2 wires.

[1990LTD]

No, see, I know what you're saying, but I don't actually know how to make the connection between two wires. I do not know how to make one wire connect to another wire. I have no idea what a butt connector is.

[Bowman85merc]

on my 85 we cut the green wire from the origanal regulator plug stripped the wire back and crimp a butt connector on (the one you linked to), then took the green from the 3g plug stipped and crimpped in the other end of butt connector.
ran yellow wire from 3g plug to power lug on aternator, then took 4ga wire from alt. to a 150 amp fuse that was for a amp then from there to battery side of solenoid.

[1990LTD]

I have the crimping tool but it's the actual connecting of wires that confuses me. How do I put two wires together? How do I wire up a fuse between the batt and alt?

[Bowman85merc]

you need one of these

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92410

or a big pair of pliers and sqeeze real hard with the wire stripped back about a 1/4".

when dad did his mark vii he didn't what to cut up the origanal wiring so he just used a spade connector on the green wire from the alterntor and plugged it into the geen wire on the regulator plug and taped it real good. so if he ever wanted to go back everthings there.