Alternator Wiring Conundrum

[SoCalExile]

Here's the situation I find myself in:

Battery wasn't holding a charge, so I took the alternator in to the local parts store for a check-up. It was a Delco-Remy that was in the F100/LTD. You see, the Goose originally had a 240/3 speed manual combo, which a previous owner swapped out for a 400/c6 combo from a 71-72 full-size car. It failed the test and I got a replacement alternator with all the plugs and posts matching the original, in the original places:



You see it has a plug in there. Problem is, there is no plug on the motor. Also, I have a bit of a shortage of contacts for this year truck. These two wires were all that was connected:



Those two wires run to the voltage regulator....


...and the starter relay:



So the question is, what did Bubba do to this truck and what do I need to do to hook this up properly?

Thanks in advance and

[fordman]

exactly. go get the alternator for the truck not for the car or a gm type of thing.

[FreakysFords]

The 3g swap is EASY.

All you need is a 3g alt (got mine from a stang, it's 130 amp), heavy charge wire (from same donor would be good), mega fuse (same donor would be good), POSSIBLY a longer tension bracket (can extend yours if needed, I didn't have to) and the pulley from an early Ford externally regulated alternator (I just did one for a friend and tired the pulley from a GM like in your pic and it works fine).

The wiring diagram is easy to follow. Several have posted it here, but there's 3 different wiring methods and the loop method is by far the easiest. Then all you'll need is a volt meter to replace the ammeter in your truck. (which I haven't yet done).

It's a worth while install even though it's simple. If you plan to add electrical accessories to your bump, you'll be glad you did it.

Frank

PS: someone recently posted several good wiring diagrams to a single thread, I'll try and find it for ya.

[SoCalExile]

Wifey's wondering why the GM-type alternator set-up it has won't work - or will it?

[ForingaMex]

Check this out.
http://www.fordification.com/forum/view ... =8&t=13062

[Thunderfoot]

If it was already mounted to the engine and the pulleys lined up good and all, you can use that one... Do a quick search on the internet on wiring a 3 wire GM alternator or even GM alternator in a Ford Here is one I found. http://www.rowand.net/Shop/Tech/GMAlternatorInAFord.htm It looks like the one you have is an internal regulated one so you wouldn't use the ford regulator.

[SoCalExile]

LOL. The Goose really is a Frankenstein. After I drove the truck home I noticed the voltage regulator was unplugged so I plugged it back in. I wonder if that might've caused the alternator to finally kick the bucket (the guy at the store said the "diode was bad").

Well I guess I'll use the new alternator as a 1-wire system like the old one was. Good thing I saved the spacer.

I guess Bubba does know a thing or two.

Oh, and !

[fordman]

that probably killed the diodes when it got plugged in.

[BobbyFord]

I have that same GM alt. on my '63 (replaced the generator), but I wired it 25 years ago and cannot remember how...
Also it appears that your truck still has the external regulator and that GM alt. has an internal regulator.

[heviarti]

I've got a '70, and I installed the Delcotron. Works like a charm. I can take pics of my wiring if you need. I'm willing to say Bubba installed the Delcotron because that's what John Deere uses... same as me. I was actually here in the electrical forum to see if anyone knew what to do to get my alternator light to shut off.

Someone said 'put in a diode' but couldn't tell me precisely where to put it. I tried wiring the diode as shown in the MSD 6A instructions, but that didn't do it.

I admit, having the alt light as a 'your ignition is on' light, and knowing to worry if it dims is fine, but I think it's time to get the light to work right. Thoughts?

[fordman]

you say the light wont go off. well that is a dummy light cluster. is this john deere alternator wired for dummy lights or gauges. that could ebt he cause. either that or the alternator/regulator is bad and isnt working.

[heviarti]

I know the alternator and battery are fine. I've been running the truck ten years, and only replaced a battery once... and that battery was no good when I got it. (875 cranking amp battery by champion, bigger than my battery box) Luckily it was enough battery to start a 300 six for a year and a half...

I can photograph the mods I made so folks can see it. The Delcotron has always been a superior alternator, and many things are available in that form factor.

I need to go to Durobilt and get a nice chromed one with a dual v belt pulley, so I can install two belts.

That being said, there has to be a method to turn that light off; that is proven by the fact the circuit existed on the truck in the first place. There's probably someone here who knows how to make it happen. Hypothetically, if you just had a cable that ran from nowhere supplying 13.6 volts, the same circuit could be built to light a lamp when delivery voltages are less than storage.

The first rule of jerry rigging is 'supply the the part with what it wants at both ends' in this case the alternator wanted rotation at one end, and an output and exciter wire at the other.

The idiot light circuit has half of what it wants... a good bulb abd a ground. Now I just have to figure out how to supply the discriminator part of the circuit between the alt and the light.

[heviarti]

Here's a pic of the mods made to accept the Delcotron. at some point I need to put a proper connector on the harness.

[fordman]

oh a gm alternator. i had a diagram of that once. or i seen one anyway. it looks hooked up correctly from what i remember. for some reason freakyfords name comes to light when i think of who may have showed me how to do it. and for some reason i want to say the regulator controls the light coming on in the dash.

[heviarti]

Yeah man. Delcotron. I lost several stock units, and replaced it with the Delcotron no probs since, cep'n the light's always on.

I pretty much follow a simple strategy: If it fails cut away everything you don't need, then replace it with something of known good quality preferably from John Deere.

Which reminds me, I need to buy the JD heavy duty flasher for my pickup...