620 wiring

[rollinsrods]

Does anyone have cutoff dates (approx) for wiring updates on 620s? Engine harnesses are never the same that I find. I don't know if I'm constantly running across swaps/upgrades or if Nissan had an overlap in harnesses.  The color coding is ridiculous considering it's a 6 fuse/ 35 amp system on the same body style over 8 years with essentially the same engine.  I have 2 1976 620s and their harnesses are significantly different, as are almost every 620 I've found at salvage yards.  I'm not just talking added features-color codings are driving me insane.  I'd rather not unwrap every harness or ohm every wire to find out what wire ends up where.  LOVE THESE TRUCKS! I'd like to approach mine like they are as simple as they seem.  Datsun Mike or some other senior member, please help.  Even a link to a reputable source for diagrams would be great!

[datsunaholic]

Are you sure they were both '76's?  I've had 3 76 620s- one longbed and 2 KCs and the harnesses were identical.  My 75, OTOH, was VERY different.  My '77 was different enough that it wouldn't work (had all the same wires but different connectors at the steering column for the turn signals and high beam).  Every year 620 used a different harness, though.  Plus there were pretty significant differences in California vs Federal vs Canadian harnesses, especially since California added electronic ignition several years before it was added to the Federal and Canadian Datsuns.  That could be part of your issue.

 

I've never had discrepancies with the factory wire colors vs the factory manual's diagrams- they've always matched, except when some prior owner has hacked the harness to death.  Even then, aside from the one melted harness I had I was able to get the original harness working again.

[yello620]

I have never had any issue with wire color discrepancies either. 

 

Do you know about this page for the wiring diagrams? Should help sort out a lot of issues.

http://www.davidcmurphy.com/olddat/620tech.htm#wd

[rollinsrods]

yello 620, just went on that link and it finally loaded '77.  Don't know what was up with that, all other years downloaded and printed fine.  That was a big issue solved nicely.  I pulled parts off a '76 with a '77 swap at some point.  The guy had a nice handful of Datuns, so I wouldn't be surprised if he moved everything over to get the nicest body running best.  I guess I'm just getting trucks around here with swapped stuff.  Not surprising, looking at the major changes over a short period.  Still different, coming from an Amerian muscle car background when everything was pretty similar wiring with body style.  My bad, time to learn more Datsun...

[Cardinal Grammeter]

Wow, there are a bazillion different part numbers for the engine room harness #1 in the pic for the post 1974 models:

 

1 HARNESS-ENGINE ROOM  

24012-B8014 AUTO,FED 7508 7607 1

24012-B8061 MANUAL,FED 7508 7707 1  

24012-B8063 OP COOLER MANUAL FED 7608   1

24012-B8071 AUTO,FED 7608 7707 1  

24012-B8073 OP COOLER AUTO FED 7608   1

24012-B9102 MANUAL,CAL 7508   1

24012-B9112 AUTO,CAL 7508   1

24012-B9161 MANUAL,CAL 7608   1  

24012-B9163 OP COOLER MANUAL CAL 7608   1

24012-B9171 AUTO,CAL 7608   1

24012-B9173 OP COOLER AUTO CAL 7608   1  

24012-B9800 MANUAL,FED 7708 7806 1  

24012-B9801 MANUAL,FED 7807   1

24012-B9803 AUTO,CAN 7807   1

24012-B9803 AUTO,FED 7807   1  

24012-B9803 MANUAL,CAN 7807   1

24012-B9805 OP COOLER MANUAL FED 7708 7806 1

24012-B9806 OP COOLER MANUAL FED 7807   1  

24012-B9810 AUTO,FED 7708 7806 1

24012-B9815 OP COOLER AUTO FED 7708 7806 1  

24012-B9817 OP COOLER AUTO FED 7807   1  

24012-B9861 CAMP FED 7807   1

24012-B9866 OP COOLER FED CAMP 7807   1

24012-B9900 MANUAL,CAL 7708 7806 1  

24012-B9902 MANUAL,CAL 7807   1

24012-B9905 OP COOLER MANUAL CAL 7708 7806 1

24012-B9907 OP COOLER MANUAL CAL 7807   1  

24012-B9910 AUTO,CAL 7708 7806 1

24012-B9912 AUTO,CAL 7807   1

24012-B9915 OP COOLER AUTO CAL 7708 7806 1  

24012-B9917 OP COOLER AUTO CAL 7807   1  

24012-B9962 CAMP CAL 7807   1

24012-B9967 OP COOLER CAL CAMP 7807   1