AWSX1686
AWSX1686 Dork
5/7/18 10:31 a.m.

I have completely re-done all the wiring in the challenge car and the last piece is the alternator wiring. I'm trying to figure out what the pinout for the 3-pin plug on the alternator is, but for the life of me I can't find any info online. 

 

It is a stock alternator for an 88 Ford Thunderbird Turbo Coupe, but so far I have not been able to find any info on it. 

 

Here's the alternator:

 

Here's the part number:

And here's pictures of the connector:

 

It seems like it's some version of a Ford 3G alternator, since the cooling fan is internal, but everything I have found says that the 3G alternators have a large case (2 holes in between the ribs) or a small case (4 holes in between the ribs), but this has 3 holes in between the ribs... Also the 3G alternators I've seen have the same 3-pin plug, but also a single pin plug as well. This one just has the 3 pin plug. 

 

So...

Do any of you know this alternator to know the wiring pinout?

Or, do the I, S, and A markings on the casing near the connector give enough information to derive a pinout?

volvoclearinghouse
volvoclearinghouse UberDork
5/7/18 10:52 a.m.
AWSX1686
AWSX1686 Dork
5/7/18 11:01 a.m.

In reply to volvoclearinghouse :

That could be very useful, thanks!

 

So according to that, mine would be:

I - Warning Lamp (Probably unused in my case.)

S - Stator Pulse, because Ford. Or possibly battery sense. In either case I'm not exactly sure what to do with that. 

A - Battery (Should go to the main terminal going to the battery wire.)

AWSX1686
AWSX1686 Dork
5/7/18 11:04 a.m.

Also, separate question. The main wire from the alternator to the battery, should go directly to the battery correct?  I guess it doesn't draw anything when nothing is happening?

I only ask to make sure I put it on the correct side of the cut-off switch. I'm pretty sure I want it on the battery side though, so when you turn the cut-off switch off, everything shuts down.  But then the alternator terminal is always hot. As long as that how it's supposed to be, great, I just want to make sure. 

volvoclearinghouse
volvoclearinghouse UberDork
5/7/18 11:08 a.m.

In reply to AWSX1686 :

Be careful, if it's anything like the Delco (GM) alternators, the warning light is actually needed.  Or, at least, some bit of wire with a nominal resistance to it then connected to the positive terminal via the ignition switch.  

Stator pulse- may be able to check that with a voltmeter while turning the alternator to see if it goes on and off.  May be able to drive the tach from that.  

AWSX1686
AWSX1686 Dork
5/7/18 11:08 a.m.

Hmmm, this seems to show the "I" connection as going to ignition on. Not my exact alternator, but should be close.

Ranger50
Ranger50 UltimaDork
5/7/18 11:13 a.m.

S position is the self ignite. Basically tells the alternator is start charging. In my 5 seconds of google-fo, says S to S on the alternator, based on the wiring diagrams I see, and you have a "crappy" 2G version. You could/should just put on a 130 amp 3G in its place with no fab work.

 

AWSX1686
AWSX1686 Dork
6/5/18 11:50 a.m.
AWSX1686 said:

So I tried messing around with this a bit. 

In these scenarios, assume the car is idling:

-ISA Plug not plugged in, no output. 

-"A" wire of the ISA plug hooked to the output terminal, output of ~16v.

-Going off of the 2G wiring, I tried putting 12v with a bulb inline to the "I" wire on the ISA plug and there was no change, output still ~16v. 

I tested this with both the alternator that was on the car when I got it, as well as the identical alternator off of the parts car. 

 

Any further ideas?

 

I also have a 3G alternator on order, but if I can make one of these work, that would be better for challenge budget. 

 

Greg Smith
Greg Smith HalfDork
6/6/18 5:58 p.m.

Have you tried grounding the Sense (Stator?) per your 5/7 pic? I think both units are just putting out max voltage because the regulator isn't seeing what it needs to see. Both diagrams imply there's another connection somewhere on the alternator...

http://easyautodiagnostics.com/ford/2.3L/alternator-wiring-diagram-1

Or is there another location to connect the S like your diagram above & the one linked here?

 

pjbgravely
pjbgravely HalfDork
6/10/18 10:51 p.m.

On that Ford alternator, the indicator lamp is part of the charging circuit. It lights only if there is a problem with the alternator. There is a resister in parallel with the lamp. When I put the alternator on a tractor I took the whole harness out of the donor car to make it work.  You should be able to find the resister value on the wiring diagram of a Ford car of that era.  You could try a Potentiometer from I to ground and adjust until it works. .

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