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Re: Ignition Switches

To: Robert.Long@CSDInc.com, datsun-roadsters@autox.team.net
Subject: Re: Ignition Switches
From: walter@omni.sps.mot.com (Thomas Walter)
Date: Tue, 13 Apr 99 12:21:01 CDT

Robert,

Usually there are quite a few variations in the datsun roadsters
on the ignition switches. After a few folks have messed with them
over the years, you find MORE variations.

FIRST:

Think of what the function of the ignition switch is:
1. Turn everything off.
2. Power the acc: radio, fan, wipers
3. Power the "ign": ignition coil (though the ballast resistor)
4. Power the starter: starter powered up
                      acc are NOT powered
               4.1    power the coil via the ballast ('66-67.5)
               4.2    power the coil directly (bypass ballast) '68-'70.

Figure one wire is the "hot" to all this.

So with conditions to all this, you can see you need FOUR WIRES on a
'66-'67.5, and FIVE WIRES to a '68-'70.


I'll sit down with my ohm meter (that buzzes) and start playing with
the switch making a sheet of paper that is "5 x 5 square). Across the
top I'll put down "OFF" "ACC" "IGN" and "START", down the bottom
I'll label conection 1, 2, 3, 4, 5. 

I'll try every possible combination to see what is connected to what
during the "condition" at the top. Repeat for each. 

Then I will go back to the car, and locate the "power" source. With
a test light, or a meter, you should find ONE wire with the battery
voltage on it. Once I locate that wire, I start "playing" with a 
short jumper wire (two male connections on it, 20 amp inline fuse)
and figure out what lead powered up the fan/wipers (acc), what
one hit the starter. 

Three wires down, two to go. With the distributor
cap OFF and the points closed (grounding the coil), car in neutral)
I'll jumper one of the "ignition coil" leads, then check for the
voltage at the "coil + terminal". If it is about 8 volts, that is
the lead for "running", if at full battery voltage, it is the lead
for "starting". You need the points closed to measure that correctly.
(note '63-67.5 did not bypass the ballast resistor like the '68-70
models do).

Now with my note book, I have a pretty good idea of what goes to
where. I'll go back to what two wires were connected on the "Acc"
position. OK. Then I will look at the "START" position, as I know
the accesories are to be off, so it will be left unconnected. Boom
I know the "power" and "acc" connections. I'll then figure out
what wire for normal "on" is, as it will be connected to the
"power" and "acc" terminal. THREE DOWN, one left ('63-'67.5) for
the starter function. two left ('68 '70).

On the Kanto Seiki switches: take a q-tip with alcohol. Clean the 
back area of the switch carefully. If you are in luck, you'll find
the "magic decoder ring". Letters are A, B, R, S, IG.  Thankfully
in english:
A = acc
B = battery
R = run (actually start: ballast bypass)
S = starter
IG = ignition (normal running).

Odd thing is the "R" anhd "IG" functions seem to have swapped around
on different switches!

With luck... all done.

Oh, did I mention I love adding little fusible links to the power
lead from the battery (which really comes off the stud on the starter
the battery cable is connected to).

Cheers,

Tom

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