wirring alternator

[Jovan Munoz]

so i am doing my engine swap i have a datsun 620 1979 and i droped in an sr20det s13 so now i did all the wirring but i am having trouble wirring the alternator to the stock wirres on the truck anybody now how to do this ?

[banzai510(hainz)]

A 79 truck should be already wired for a IR alternator.

 

if the T connector is the same just use the SR alternator. and hook up the + output wire.

[datzenmike]

I think it will have this plug Hainz.....

 

 

I made this handy jumper so that I could swap the old alternator back in if I want.

[banzai510(hainz)]

yeah I forgot.

 

the KA trucks I think still had the T connector????I forget havent seen this talked about in awhile.

Napa sells connector ends so Javon you can make this jumper to work for you or just use the old 620 alternator to get it running for now But I think those might be 35amper luck a 50amper

[datzenmike]

The 720 were 50/60 amp so the D-21s would be at least that much and like most sensitive EFI motors they are usually much higher to keep the voltage up when idling with heater, lights and wipers on.

 

edit: 87 and up D21 and Pathfinders are 70 amp.

[desert skipper]

As an "old fart" newkid. . . . . . .

 

What is a KA truck you mentioned above...?

 

I have an 81 720 that may need alternator work...minor or major.

Disability sucks. I will need to "special order" a new alternator if major.

 

The rubber boot connector on the back for a "T" was loose.

Now gone, but with crimp-on connectors (2) underneath.

My local wrench tested the charging system with his test meter,

but it was jumping all-over. It was jumping from 17-18 volts down to 10 -11.

I hit the highbeams and it did not flatline or dump.

 

Do you have a napa part number for the connectors ?

[datzenmike]

No. Just cut them from a junk Yard Datsun between '68 and '86. All the same. Toyota and lots of Jap cars and trucks us Hitachi alts. Cut with long leads and splice and solder into your wires.

 

Jittery charging could be badly grounded alternator... there is a lug with a black wire for this on the back of the alt. Check the ground cable where it bolts to the intake. Check the positive cable where it bolts to the starter lug. Last of all clean and tighten the battery posts and cables.

 

The brushes may be worn out and need replacing. 23135-Q4601 at the Nissan dealer ($16) probably cheaper at NAPA

[510rob]

Just so it exists in writing somewhere other than PMs, I sent this to Jovan for his alternator wiring to go from his 1979 620 harness to his SR20DET alternator

 

 

620 Thick white/red = main current connection to the 620 harness = SR20 Thick white

 

620 Black = ground (body ground) = SR20 Black

 

620 Yellow = voltage reference (the S terminal on the alternator's T-plug) = SR20 Thin white

 

620 Thin white/red = switched power (the L terminal on the alternator's T-plug) = SR20 thin white/red

 

 

The datsun/nissan of this vintage (with internally-regulated alternators) all have four terminals. The newer alternators like the SR20 ones might have a different connector for the S & T terminals, but the concept is still exactly the same. I did a write-up a while ago on the 510 Realm that explains, from the alternator's perspective, what each terminal does and how to connect it --> CLICK HERE THEN SCROLL DOWN A FEW POSTS

[Jovan Munoz]

I did the wiring exactly how 510rob told me and it worked perfect thanks rob