datsun 521 under hood relays (which ones are which?)

[PHANTOMa]

So I pulled the entire harness from a 521 for my 520 and I know it'll work but some of the relays were missing and I have no idea which ones are which......there's 3 on the passenger side wheelwell and 2 on the drivers side.....and after that i'd need to know which wires by wire color go into each spade connector for each of the relays......just sucks cause no diagrams ANYWHERE has this information......any help is appreciated thanks!!

[DanielC]

Maybe this will get you started.

The three red wires are for the headlight relay. Red with yellow, power in from fuse box. Red with black, power out to low beams. Red with white, power out to high beams.

In the relay, Red /w black is normally connected to Red /w yellow. Red /w yellow also is connected inside the relay to the relay coil, and the light green wire grounds the coil, on the turn signal switch, causing the relay to switch to high beams.

 

The next three wires forward are for the horn relay.

Here is a wiring diagram.

 

This diagram is missing the two relays used with USA dual point distributors. but id you have either weber carb, or a five speed transmission, or Matchbox distributor, you do not have all the components to use those two relays anyway.

[PHANTOMa]

Holy balls yessss!! Thanks dude very much!.....don't suppose you know which position the wires go in the relays.....??......like........ 1_____2_____3

[DanielC]

The relays should have numbers on them. I can do some investigating a little later. on the 521 I am working on, the horn relay has raised letters stamped on top, but the headlight does not.

My headlight relay is also wired a little differently, to remove headlight current from the stock fuse box, and all the headlight switch wiring into the cab, and back out again.

 

If you have a L-16 521 harness, the ignition coil on that harness is mounted on the left inner fender. I believe 520 ignition coils were on the firewall, just right of the engine.

 

It is a bit of a hassle but you can unwrap the stock wiring harness, and remove the wires you do not need. you may also need to do this to move wires around to where your under hood parts are.

[PHANTOMa]

Yeah its an l16 harness and you're exactly right about the coils.....I'm gonna be using an s13 sr20de in a few months so I can just leave the coil wiring where its at thankfully.......and yeah If that's the case with those extra relay wires then I'll just de-pin and removem.....everything else is where it needs to be I think.....fersure please keep me posted on the decyphering of the letters on that one relay.....btw what's the difference in the harness for a 5 speed.....just less wires right?

[PHANTOMa]

Holy crap.....idaknow how I missed it the first time but your diagram has exactly what I needed plus the info you gave me! Forreals dude thanks alot!

[DanielC]

Sometimes the relays are numbered, sometimes they have letters.

This is the horn relay.

There is a "B" a "S" and a "H" on it. "H" goes to the horns. "B" is from the battery. "S" goes to the steering column.

 

This is one of the emissions relays.

I had to lightly wire brush the side of the relay to see the numbers.

Your headlight relay will have four numbers.

If you look at the wiring diagram, you will see numbers, or letters on the wiring diagram on the wires corresponding to the relay.

[dat521gatherer]

 

green/blue in the middle

 

 

[PHANTOMa]

Oh damn dude! That's exacccctly what I needed! Thanks again man....hella pro stuff