Troubleshooting a 240Z Dash Wiring Harness

[Namerow]

I took my dash out of the car ('70 Z) last year to do repairs to the cracked cap.  As part of the process, I removed the dash wiring harness and have now finished giving it a general clean-up (which included cleaning all the connectors and spiffing up all of the metal contact surfaces for the electrical terminals -- male connectors sanded, female connectors treated with De-Oxit).  All the gauge bulbs have been replaced.  Also:

 

• The harness looks to be in good shape and unmolested.  No visual signs of melt-downs.
   
• The fuse block has been replaced with a NOS unit (the original had the typical burnt circuit)
   
• All the gauges have been cleaned up and the meter movements bench-checked for proper operation (excepting the Tach and Speedo). 
   
• The Combination Switch, T/S Switch, and Hazard Switch have all been stripped and internal contacts cleaned, per write-ups posted on the CZCC site by others. 

The switches and gauges could all be conveniently connected up to the dash harness as it sits on my workbench.  The metal dash armature (frame) would seem to provide the common ground circuit -- just as it does when the dash is installed in the car. 

 

I bought this car in good, but non-running condition. It has relatively low miles on the odometer.  Before putting the harness back in the dash and putting the dash back in the car, though, it seems like it would be a good idea to do some checks for electrical continuity and possible shorts (I don't ever want to see the underside of the dash again if I can help it).

 

So here's my question:  Can anyone suggest a resource for how to carry out a systemic check of the harness wiring/circuits?  There seem to be infinite ways of going about this and I would prefer to avoid re-inventing the wheel if someone has a plan or strategy for how these checks can be done in an efficient way.

 

Note 1 - I have a color-keyed wiring diagram for the 70 Z, created by someone named Sully Ridout (CSCC member?).  It seems to be accurate enough (excepting a little confusion over the correct pairings of the four aux gauges -- something which even the factory diagram got wrong).

 

Note 2 - The Ignition Switch is still in the car -- although I could remove it and bring it into the workshop if that would make system checks easier/faster/more accurate.

[heyitsrama]

For continuity checks when i build small electronics i normally use a multimeter with the setting that looks like  >| ))) 

I can just imagine that you run along the wires end to end, to make sure there are no cuts or jumps along them? I can't think of any other way to test them out. Unless running a current through them and testing out various smaller lights to ensure connection.

 

Did you upgrade to relays for all the lights? Last time i was working with mine my turn signal light started to melt 

[Mikes Z car]

  I would think checking continuity might be done with an ohmmeter that can read down to tenths of an ohm but would require some very accurate wire identification.  My 1970 dash wiring had three issues, the two thick white wires that carry battery current showed overheating (blackened connector vinyl) at the connectors that end above the passenger's right knee (U.S. car), the T/S switch didn't work reliably and neither did the headlight switch.  For the two white wires I soldered the wires to the connectors and gently squeezed the female connectors together on the end closest to the wire to increase gripping action followed by deoxit and dielectric grease on connecting surfaces.  The T/S switch and headlight switch were cleaned and relays installed to take the load off the switch.  No problems so far.