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Datsun 521 Electrical help


Jacobs601

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Hey,

I got a 1969 521 I desperately need help with. I'm in the process of restoring this one but when it comes to the electrical, I'm not so great at it. The truck is pretty much complete but the previous owner cut the fuse box out and removed the coil and resistor. I'm having trouble trying to figure out how to wire in the new fuse box and coil. I've found all of the wiring diagrams but they are no help to me cause I can't under stand them. I think I got the coil figured out but not the fuse box. My fuse box have eight wires going into one side and four going into the other side. Could someone explain to me what color plugs to what and which of the fuses should be tied together. Or even give me a call. Any help would be greatly appreciated. I just can't understand these complicated wiring diagrams.

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Here is a wiring diagram, in color, that might help.

521wires.jpg

There are four wires on the battery side.  A wire directly from battery positive, to the fuse box.  A thick white wire, this wire supplied power to the ignition switch.  A black wire, with a white stripe comes from the ignition switch, is hot with the key in run position, and a second black wire, with a white stripe goes to the ballast resistor.  A black wire, with a red stripe then goes to coil positive.

 

This page has some pictures of a new blade type fuse box installed in a 521.

http://community.ratsun.net/topic/49698-my-dragon-datsun-521/page-5

 

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There are some ground wires that tend to removed in 521 trucks, over the years.

This is a negative battery cable.  The big lug goes to bolt by the fuel pump, NOT a fuel pump stud.  This grounds the battery to the engine.  The pig tail with the small eye goes to the alternator frame, to ground the alternator.

BlockEnd_zps702f4f48-1.jpg

 

The battery end of the cable above.

BatteryCableEnd_zpse72afc2b.jpg

There is a second black wire, connected to the alternator frame.  This wire goes to the voltage regulator, and is on one of the bolts that hold the voltage regulator to the inner fender.  It you remove the voltage regulator, and replace the externally regulated alternator with a more modern internally regulated alternator, this ground wire from the alternator frame to the inner fender must remain in place.  If you lose the cab sheet metal to engine ground connection for any reason, the cab will ground through the throttle cable, and destroy it.

 

The engine needs to have a good ground to the truck's frame.  The cab also needs a good ground to the frame, you cannot and should not depend on the cab to frame bolts for this.  This is the function of the wire from the alternator frame, to a voltage regulator mounting bolt.

If you have unusual tail light problems, often they can be fixed by running a ground wire from each tail light frame, to the frame under the bed.

 

This a picture of the battery to fuse box connection.

RatsunBatt2_zpstne60ic6.jpg

 

This is a picture of connections to a 521 fuse box.

FuseboxClose_zpswv5eoj04.jpg

This extra orange wire, with an inline fuse feed power directly to a extra relay, by the original headlight relay. 

AuxHeadlightRelay_zpsupxvshtg.jpg

This is that extra relay.  The orange wire goes to pin 30 of the added relay.   The red with a yellow stripe wire on the original headlight relay goes to pin 86 of the added relay.  You ground pin 85 of the added relay.  Then a short jumper connects pin 87 of the added relay to the empty pin on the original headlight relay.

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OK you got the drawing on the first page, This is EZ get a meter and ck it out.

If it has the round lug its the + output of the alt.  you can ohm ck this with a meter ands it will go to the voltreg and the batter post. its the commom positve wire. ck with drawing.

My 521 the wire will be wht. red sripe  but i think goes solid white soemwhere under tape.

 

YOu have a early 521 as it has a funky harness to the alternator. Some have cable harness adapters when you get it for a 69

 

dont throw that alt away intill you knw a new one with work (u can get it rebuilt.

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Great, thanks. I've rebuilt my alternator already. I do ok with the mechanical but when it comes to electrical diagrams, it might as well be Chinese arithmatic. I'm gonna keep plugging until it works. It's a running and before to long I'm gonna be driving. Thanks for yalls help.

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