Internal regulated alternator not wired up properly. PLEASE HELP

[erikcarter]

I have a 72 goon with a l20b and a 80 210 internally regulated alternator. I did a mild wire tuck three months ago and I put on a aluminum turnbuckle on my alternator instead of the stock bracket. I ran the car for a couple months after the wire tuck with no problems, I had the belt too tight with the new turnbuckle and ruined the bearings in the alternator. After I got a replacement alt the charging system has not been working right. When I first put on the new alt which was wired the same as the old, I was making to many volts like 17. Then I started to make barley 12 on my volt gauge. I talked to some people and discover that I needed the charge light so I wired one up but it doesn't work right either. It seems like the alt isn't putting any volts out through the T connector int the rear. I had it tested and all was well with it, so I know that I am missing something. Please help.

Thanks, Erik

[wayno]

I don't know a lot about this subject, but one of the wires in the "T" connector is supposed to be 12 volts going into the alternator, that makes the alternator charge, if it doesn't have the 12 volts going in, it won't do anything as it isn't activated.

There is a way to make GM alts. a one wire alt, but it isn't really one wire, as there is a short wire going from the "T" connector to the main charge wire going to battery, therefore it is hot/activated all the time.

Do you understand, I don't know which of the "T" connectors is the one that is supposed to be hot, but one of them is 12 volts when you turn the key on.

[Pacific coast Datsun]

PM Hainz..he has a wiring diagram for swapping to a IR alternator. I used it when i did my swap.

[datzenmike]

If it was working with the old alt and suddenly there are problems with the new, it would seem to me that the new alternator IS the problem.

[thisismatt]

 

...where from the plug on the alternator you have Y and WB (or N and F respectively).

 

Y or N is often known as your "sense" terminal, which senses the system voltage and tells the alternator to adjust the output as necessary. This lead should technically run to somewhere where voltage is important, instead of jumping straight back to the alternator or battery, since it will read the highest voltage here and not output as much as you might want for somewhere further down the line, say at the dash. But it usually works fine to just jump it straight away.

 

WB or F is your "field" terminal, for field excite, and it runs through your charge light. This terminal gets power from an ignition switched 12v source and then through the charge light. It energizes (excites) the field windings inside the alternator to create the magnetic field needed to start outputting current. When the alternator fails, or when the engine isn't running and the ignition is turned on, this terminal effectively goes to 0v (ground) and causes the charge light to come on. Once the alternator is running it outputs 12v on the field terminal which equalizes the 12v coming in on the charge light circuit, meaning the charge light has 12v at both sides and therefore doesn't light.

[erikcarter]

Matt--

I have the yellow hooked into the back of the alt with the big white red stripe from the starter and going to the fuse block. (positive terminal on the alt). I have the white with a black stripe going to a light under the dash and the other side of the light is to a keyed hot. I think I have it set up the same as your diagram but I will try taking the yellow and running it into the cab and finding a keyed 12 volt in there.

What do you guys think?

[datzenmike]

I did a mild wire tuck three months ago and I put on a aluminum turnbuckle on my alternator instead of the stock bracket. I ran the car for a couple months after the wire tuck with no problems, I had the belt too tight with the new turnbuckle and ruined the bearings in the alternator.

 

Was working fine

 

 

After I got a replacement alt the charging system has not been working right. When I first put on the new alt which was wired the same as the old, I was making to many volts like 17. Then I started to make barley 12 on my volt gauge.

 

Problems after the alternator swap.

 

I talked to some people and discover that I needed the charge light so I wired one up but it doesn't work right either.

 

Turn key to on... red CHARGE or ALT light on dash must be working.

 

 

 

A new alternator does guarantee that it is a good working alternator. They are often cheap re build/re manufactured with cheapest parts and labor and can be bad right out of the box..

[erikcarter]

The light has never worked since I tried to install it. As for the alt I took it out Saturday and Phil tested it and it was working fine. I haven't had a charge light in the car for a year before this weekend.

 

Edit

 

I am confused to how it worked before because all I had hooked up was the yellow to a relay with no light. I also forgot to say that the new alt is a new style off a sentra with a wire adapter to the old T connector. I am a little Leary of the new style, wondering of it is needs something more

than the old style?

[datzenmike]

Then your 'wire tuck' has caused a problem. Maybe some thing is loose or rubbing. You did say it was working just fine

[erikcarter]

Yeah it was working fine. I am sure because I was scared shitless after I did it so I watched it like a hawk.

[banzai510(hainz)]

this new alternator you got what was it for.?????

 

I seen where people put the stock EXTERNAL reg alternator back in when the car is coneverted to IR type alternator.

 

get a new alternator for a 1979.200sx.

 

your plug where your olf volt reg was should have 2 wires.

white and yellshorted together

white/red shorted to the whit blk.

 

The T connector eshould be hooked up just like.

 

the T connector should get voltage when Key is On. But I just measure across the battery if you not getting good voltgae ai look at the fuse box to see if a fuse is blown. clean put new fuse and try again.

 

 

as for a light under dash? fuck how that got there.?

 

 

buy this or a in dash volt meter, so one can monitor the system before is really goes bad. Trust the gauges.Ignition light is a little to late when they come on.

http://www.equus.com/Product/3721/Battery-Monitor