Wiring 620 alt with Ext. Reg.

[KFunk740]

Previous discussion: http://community.ratsun.net/topic/43106-ign-light-when-should-it-be-on/

Was hoping I could get more direct info in this forum.

 

OK, I've got a J13 in my L320, and it's got a 411 style alternator in it that I can't find through any source

 

I just need something in it and charging, and fast. It's my primary transportation right now, and I need it for hauling things. I've just been charging the battery every time I park it somewhere with an outlet.

I was thinking that all of the trucks were fairly similar, and the alts looked the same, so I just had Autozone order me one for a 620, which required an external voltage regulator. I don't mind having the external VR, and mine is nearly new. But, I ended up with one with a T-connecter, that has 2 wires (stator and field). My old alt had a 6 wire harness/plug.

 

Is there anyway I can make this work tonight with a little soldering, or should I take the alt back and get something from a different model (510)? I'm extremely busy and have no time to research wiring diagrams, study circuits, or modify things right now, unfortunately. Moving to a new house and pressed for my time on getting several things done.

 

Thanks for your help, and sorry I can't research much on my own.

[DanielC]

I am going to suggest that if you want to use an external regulated alternator, you should get a matched set, alternator, and voltage regulator, from the factory. Good luck finding a 40 years old car with the OEM alternator, and voltage regulator, in a junk yard.

 

"I've got a J13 in my L320, and it's got a 411 style alternator"

 

If I remember right, a L320 had a 1200 "E" engine, a generator, and a voltage regulator for the generator. A generator voltage regulator will not work on an alternator. Generators are way different than alternators. Add to the mess is the fact that you are doing this in a 320, and that tells me it is very likely you have an incompatible voltage regulator with a hard to find alternator, and probably wiring on the car that really does not match either the alternator, or the voltage regulator, and there is a good chance other wiring is also messed up.

 

My suggestion, try to fit a more popular Datsun internally regulated alternator to the J engine. You probably will have to make or modify the alternator mounts. You may be able to use what you have. Once you have the alternator physically mounted, you need four wires to go to the alternator.

You need a big wire to carry current from the plus out of the alternator to the positive post of the battery. On some Datsuns, this wire just goes to the big wire on the starter.

You need to ground the frame of the alternator to the battery minus, and the engine of the truck. This wire need to be as big as the big wire on the plus side of the alternator. The electricity that comes out of the alternator has to get back to the alternator.

There are two more connections that the internal regulated alternator needs.

The "L" terminal. "L" stands for "Light". you have to hook up a small idiot light that has power applied to the light when the key is on, and the engine is not running. The Alternator grounds the light when it is not turning, and the light, lights up. When the engine starts, the alternator applies its voltage to this light, and it goes off, because the light has 12 volts from the key on one side, and 12 volts from the alternator on the other side. This light hook up is necessary. The alternator uses current from the charge light to "kick start" the charging current in the alternator.

The last terminal on an internal regulated alternator is the "S" terminal. "S" stands for sense. This is the point that the alternator regulator measures the battery voltage, usually at the fuse box. This wire needs to be connected to an ignition switched positive power source. If this wire is not connected, the internal regulator does not know that the battery voltage is. If this wire is connected all the time, it will drain the battery down.

 

The alternator frame must be grounded to the battery. Do not depend on the mounting bolts of the alternator to ground it. On a Datsun truck you must make sure the battery (and alternator frame) are grounded to the cab of the truck, the frame of the truck, and also to the bed of the truck.

 

 

I know you are pressed for time, and do not want to spend time now to fix this right.

This is reality. Pay attention. You can make the time to fix it right, now, or you can spend more time in the future redoing what you should of done in the first place. You can fix it now, once, or cobble it together, and have to do it all again. A lot of times people think they do not have time to fix something right, the first time, and are then forced into having to do it twice. The choice is yours.

[KFunk740]

The truck also has a nearly-new external VR suitable for a 520, 620, etc., body negative, etc. Autozone lists the same alternator for the 520/620, teamed with the same VR that I have in my truck.

 

So surely, they can go together somehow.

 

I just need to know which wires to connect. Please, spare me a lecture.

[izzo]

Wow, man. Ask for help and receive some insight and suggestion from a reputable member who is very knowledgeable, and that's your response?

 

He is right, you are pressed for time but should really take the time to do this right.

[DanielC]

I took the time to try and help you? And this is the thanks I get?

 

But you also trust some chain auto parts store with a person behind the counter probably way younger that the vehicle you are trying to fix, who it just trying to sell you stuff and take your money.

 

Do you really think Datsun used the same alternator and regulator from a 1967 520 to the final year of the 620?

[KFunk740]

I'm sorry, but it's just really frustrating when someone gives me a couple paragraphs on stuff I've already read or know, and it sounds kind of condescending. It's not my first time working on an old car, or being on an internet forum. Much of the stuff said was already stated in the previous thread that I linked to, so it's right there. Of course I agree with you on most of what you said, but those aren't my priorities right now.

I also like keeping things as close to stock as possible, so I'm avoiding modernizing the truck. If I wanted a modern truck with EFI, power steering, huge alternator, etc., then I would get the entire truck. But I like my old school truck for all the little old things.

 

 

 

I just went out and looked at the truck, and it's even easier than I thought. I mistakenly said I had 6 wires in the stock harness, but there are 4. The new alt has a yellow wire and a white/black stripe wire. Factory harness has both of these, plus a black wire and a white wire. I figure the black wire is an extra ground, so that's easy to replace. Not sure about the white wire. Will have to look at wiring diagram, I suppose.

[banzai510(hainz)]

The early datsuns had soem setups I dont under stand. Esp at the alternators.

Most Datsuns have the T connectors But One I dealt with had the 4 pin type also. But I have a T to 4 pin jumper in my stash.

[KFunk740]

The early datsuns had soem setups I dont under stand. Esp at the alternators.

Most Datsuns have the T connectors But One I dealt with had the 4 pin type also. But I have a T to 4 pin jumper in my stash.

 

Yeah, that's probably something like I need. Any ideas on how its reducing 4 to 2? The white wire might need jumped to either the yellow or the white/black one. Thinking it might be one that I've read about thats an extra signal wire of some sort, that just got piggybacked onto something else in later years. With the black wire, I may just put a ring on the end and bolt to back of alternator.

[izzo]

My 69 wagon had the 4 prong connector on it. I just disconnected it, jumped the wires like on the 510 IR swap diagram, and it worked fine. That guy is driving around with an IR 620 alternator still to this day...

[DanielC]

"I've got a J13 in my L320, and it's got a 411 style alternator"

"I also like keeping things as close to stock as possible,"

 

The 1965 320 truck I owned, had a 1200 engine, a generator, and a carbon pile regulator. I think it was positive ground, if I remember correctly.

You are already a long way from stock. I was not suggesting a 100+ amp alternator from a 2012 Nissan something or other.

Just a 50 amp or so internal regulated alternator from a late 1970, possibly early 1980 Datsun.

[KFunk740]

"I've got a J13 in my L320, and it's got a 411 style alternator"

"I also like keeping things as close to stock as possible,"

 

That wasn't my choice. But I couldn't pass up the great deal on a solid, rust-free truck, that ran well. These things are pretty hard to find in general.

I'm thinking about getting the original block back from one of the previous owners eventually, if he still has it laying around somewhere. Maybe I'll take my time and rebuild it, eventually.