78 wagon alternator into 72 620?

[atkinson40]

My 620's alternator light started coming on.  No charging going on at the battery.  Went to JY and found a 78 wagon with an alternator and brought it home, installed, wired it up,  it now charges the batery, but charging light does not go out and 620 won't shut off at the key.  Opps

 

Reaearch shows me the difference is internal vs external regulation.  I read Mike's post saying the internally regulated I've installed can be easily made to work on my 72 620.  Anybody know how to do this.  I searched but can't find a topic. 

 

I'm imagining I need to bypass the external regulator somehow, but not sure how.

 

Thanks Kevin

[banzai510(hainz)]

you jumper the wires at the plug . make 2, 1 inch jumpers with male ends

 

look in the "HOW TO" section for the colors. i think its wht red short with wht blk and yellow short to white.

Dont cut no wires just look at the connector engine harness side back for the color and then insert jumper wire.

 

PS if you have a elelctric choke it will kill the battery so reads for the fix

 

then print it out and add this in your notebook so you have it

[datzenmike]

If a car alternator, i'st physically larger than the 620 one. It's a tight fit above the idler arm on the truck. Only the 620 alternator is an easy fit.

 

I just cut the external regulator plug and wires off the regulator, make the wires as long as you can. Now join the White/Red stripe and the White/Black stripe wires. Then the Yellow and the White wires together. Remove the other wire ends from the plug so they never ground out on something. Now plug this modified plug onto the engine harness.

 

Because of the previous wiring changes the choke heater relay may be perminantly ON and drain the battery over the weekend. Not sure on the early 620. If the relay is energised it will have to be unplugged. A new power source for the electric choke is easy enough. If you have an idle cut solenoid, just join the Blue choke wire to the Red idle cut solenoid wire. This is how I did my 710s. 

[atkinson40]

Thanks B an DM,

 

It's off a '78 something Datsun wagon.  I read 1978 on the door tag.  It went in no troubles at all.  It is bigger, but somehow the bottom two bolt holes and the tension arm all lined up. I need to read slowly DM's wiring note and digest.  My choke is an electric on weber and if I remember, I wired it through the ignition switch.

 

This old beater is serving me well.  I'm pouring sidewalks through my orchard and have loaded it up with 16 sacks of 90lb quickcrete and 21 cinder blocks for a total of 2028 pounds.  Gotta keep it all forward in the bed to keep the front end from floating.

 

I've also loaded the bed level with broken bricks.  I dunno what that weighed.  She pulls hard and strong.  She's an uncomfortable bitch to ride in for a 6'1" dude.  I put one of those load mufflers the kids are putting on their cars, but Led Zepplin jammin' in my buds kinda tones that down.

 

My wife's afraid to ride in her, she cruises 80 easy, rattle trap as she is.

 

Thanks Kevin

[datzenmike]

Thanks B an DM,

 

It's off a '78 something Datsun wagon.  I read 1978 on the door tag.  It went in no troubles at all.  It is bigger, but somehow the bottom two bolt holes and the tension arm all lined up. I need to read slowly DM's wiring note and digest.  My choke is an electric on weber and if I remember, I wired it through the ignition switch.

 

 

 

Then this is fine. I don't remember if the 521 has a relay for the auto choke. If it does be sure to unplug it.

[atkinson40]

Thanks DM

 

I finished it. From the wiring diagram in the "How Too Section", its unclear if you remove the wires from the regulator, or just splice the alternator wires into them with a "Y" connection. Your post indicates you cut the wires to the generator (No 'Y" connection) and I found out this was correct.

 

Thanks Kevin

[datzenmike]

If a car alternator, i'st physically larger than the 620 one. It's a tight fit above the idler arm on the truck. Only the 620 alternator is an easy fit.

 

I just cut the external regulator plug and wires off the regulator, make the wires as long as you can. Now join the White/Red stripe and the White/Black stripe wires. Then the Yellow and the White wires together. Remove the other wire ends from the plug so they never ground out on something. Now plug this modified plug onto the engine harness.

 

Because of the previous wiring changes the choke heater relay may be perminantly ON and drain the battery over the weekend. Not sure on the early 620. If the relay is energised it will have to be unplugged. A new power source for the electric choke is easy enough. If you have an idle cut solenoid, just join the Blue choke wire to the Red idle cut solenoid wire. This is how I did my 710s. 

 

Use the regulator plug. Join the wires on it. Then plug it back onto engine harness. No where does it say to cut the alternator wires.

 

 

 

Obviously if the wires are cut off the regulator, you don't need it and can remove it from the car.

[kgrantkey]

I love pictures. The how to section here is the best on any forum for any brand of vehicle I;ve ever come accross.  The IR Altenator swapp and how to convert to electronic Ingnition are two of the best mods I've made on my 620 over the years.

 

 If I had the money I'd move to California just to be closer to Ratsun members.

 

 

Roll Tide :thumbup: