Just bought a 72 pl521 just has a few minor issues... Can someone help?

[bigbeek]

I just recently acquired a 72 521 datsun pickup

it runs fantastically even though it sat for 4 years

it took 4 days of tinkering to get it to start but I'm having a few electrical issues that I'm at a loss with.

I have no power to all the rear lights and horn.

 

I studied the box and I believe I might need to re run the battery wire to the fuse box but I wanted a second opinion from other people before I jump the gun.

 

I'm a younger classic car enthusiast and this is my first project! So any help would be appreciated

[datzenmike]

The fuse box is removable so take a picture of where the wires go and remove it. Find a suitable container and soak in vinegar over night. Th vinegar will loosen and remove the tarnish on the copper parts of the box. Next morning thoroughly wash with clean water and install with NEW fuses. Fuses are not to be trusted on looks alone, always replace them. This will likely fix electrical problems you don't even know you have yet.

 

This is always a good idea for preventing problems later too.

[DanielC]

This is a good start.

 

Here is a diagram of lights only.

 

Make sure you have good grounds.  The battery negative to the engine, by the fuel pump.   There is a ground wire that goes down to the alternator frame.  There is another ground wire from the alternator frame to the voltage regulator mount.  If your truck has had an internal regulator alternator swap, the ground wire to the voltage regulator mount must stay in place.  It grounds the cab to the engine.  Without it, the cab will try to ground through the throttle cable, and destroy it.

The frame needs to be grounded to the engine.  The bed needs to be grounded to the frame.

The tail lights are normally grounded to the bed, you can add a ground from the tail light wiring harness, on the tail light frame to the frame.

[banzai510(hainz)]

I think the horn and the rear lights are on the same fuse.

replace the fuse

[bigbeek]

Thank you! I'm going to try cleaning the fuse box and I notice after following the wiring diagram that my two grounds on the rear harness were missing I'm going to also redo those and I'll post back later on what happens!

[banzai510(hainz)]

my dash lights didnt work also. on my 521

[DanielC]

Here is a pin out of a 521 combo meter.

 

If you go to this page of my thread, near the bottom, I write about testing the combo meter.

 

community.ratsun.neat/topic/30606-my-ratsun-datsun-521/page-2

 

 

To remove it, take out two screws on the bottom of the black plastic cover.   Then the cover will slide straight down, and two clips near the top of the cover will come apart.

There are two more screws, and nuts that hold the top of the combo meter. 

Remove the speedometer cable.

Very carefully work the multipin plug off the connector shown above.

[bigbeek]

after careful review i have come to the conclusion that my fuse box, and the light switch were at fault for my issues, the original fuse box cracked upon removal... who would've guessed haha. BUT i bought the parts and made a new fuse block with parts from radioshack that resemble the original box. and then i ordered a new switch..... Also  while looking under the hood we found out the ignition coil was cracked, what issues might this cause?

[banzai510(hainz)]

Buy a stock jap coil for that model year . call if good.

 

coil is full of oil. Maybe it leaked out. Maybe its nothing

[bigbeek]

doing that today. just so happened the local Oreilly's had one in stock for 20$!

[DanielC]

Nissan factory parts are very high quality.  In fact, many times you are better off getting a used Nissan part, from a junkyard, that getting replacement parts from an auto parts store.

 

If your truck still had a stock points type distributor, start your hunt for a matchbox distributor used on later L-engines.  Get the matchbox distributor, the pedestal it sits on, the plate between the two, and the electronic ignition coil.

[bigbeek]

alright replaced the battery connectors built a new fuse box with all new parts and put all brand new fuses into the slots, and still no tail lights, brake lights or rear turn signals.

on another note got the plug cables and ignition coil replaced the engine is running alot more solid now!

[bigbeek]

following the wiring diagram we finally FOUND the issue!!!! it is fixed and perfect now!

there was a break in the rear wiriing harness where it begins right under the transmission!!

we patched all the wires and everything worked flawlessly!