72 510 Auto No start - Inhibitor switch issue?

[Crashtd420]

The book I am referencing are for 510's 68 to 73.... the 3n71b transmission wiring shows no start relay... so i don't know..

I was trying to match what datsun Dave was saying he had... ah the joy of a datsun..

[datzenmike]

All I have is that shitty Haynes 510 manual. It's made for/in Britain so terms are different and the electrical diagrams are I think for only the earlier '68 or '69.

[Crashtd420]

I guess it's Dave's turn to chime in

[datsun.dave]

Thanks Crash for breaking it down - it helps to have that interpretation for sure. 

 

So - this is what I started to write...

 

"As far as I can figure out, power has to come on black blue when key is in start position.  That is where we breakdown.  Black yellow isn't constant, it only powers up when the key is turned to start.

The relay has power on black yellow with the key turned, but no power on black blue..." 

 

Then I went out to the car, wiggled all the leads and checked continuity from the black/blue on the ballast resistor back to the harness at the fire wall where I exposed the two black/blue that come up off of the inhibitor switch - confusing, I know - because the inhibitor switch doesn't have black/blue.  oh wait.  yes it does. And, I wiggled and cleaned up a couple contacts at the fuse box. 

 

My inhibitor switch has 2 black/blue coming up into the firewall harness, one of which doubles back to the ignition and one of which makes it's way to the starter relay... and my starter relay has 6 wires.  2 black/yellow, 1 black/blue, 1 black (confirmed as ground) and 2 blue/green (which I have no idea WTF they do...) 

 

And yes, my inhibitor switch has 4 wires - two black blue, and two red black (at least that makes sense.)

 

So, after tracing everything I could out on the wiring diagram, I went out to the car to test what happened to the two black/blue at the firewall when I shifted from park to drive.  Resistance went from .6 ohm to 65 ohm suggesting that the switch was doing something.  

 

Then I accidentally turned the key and started the car.  And, the signal lights work, the seatbelt buzzer works, the three gauge caution lights lit up, and everything is normal. 

 

I went back and forth in and out of gear, turned the car on and off a couple of times.  And everything works. 

 

Soooooo, clearly, I have no idea what the problem was, because I conducted pretty much all the same tests previously... I guess I chalk it up to a sticky inhibitor switch or a goofy connection at the fusebox...

 

W. T. F.

 

Upside is, I have a lot better understanding of how the system works.  And, I will carry my little jumper wire in the glove box so if the same symptoms present again, I can at least fake my way home...

 

[datsun.dave]

Sorry guys - I missed the conversation going on while I was running back and forth to the garage to figure out the wiring diagram... I took some pics that I am just trying to post so you can see my start relay...  Production date is 6/72... could be an early 73??  Is there an easy way to ad pics?  It took me half an hour to make the one for my profile pic small enough...

[Lockleaf]

Get a photobucket account.

 

Upload pics to photobucket.

 

Copy codes to the reply box and post.

[datsun.dave]

 

Almost like rocket surgery... I now have a photobucket account.  Top wire is black/blue.  Relay was free from fender for this pic to show the wires... I had also opened up the relay and the cover was loose. 

[datsun.dave]

Anybody have a wiring diagram for a 73 specifically?  Anyone know the production change over or the serial numbers by year? I will check the search function...

[datzenmike]

Try asking... http://www.the510realm.com/search.php?search_id=newposts&sid=5d084607f968635fae38e8f2da6a0f55

[Crashtd420]

So your all set.. Good to hear.... probably slight corrosion on the plugs .. by unplugging and checking you finally remade the connection .. might be a good idea to check some of the plugs for corrosion and clean them up a bit if needed.. ....

[datsun.dave]

Thanks a lot for the help guys - if nothing else, I ended up exploring a little more and finally jiggled the right wire.  I did go through and clean up all the connections on the fuse box and will work my way through the rest of the car...  I will check over on the Realm for the diagram.  Just signed up there too...  Still curious when the cutoff between 72 and 73 is... and what the differences are...