So now you've tested the starter properly, it seems OK.
But the clutch safety switch (1) should have 12 volts positive to it when the key is turned to the START position (at one of its terminals); check that. (2) And it should pass that 12 volt positive through to the other terminal when the clutch pedal is pushed fully down. Your test shows that the switch itself is working (0.6 ohm resistance, that's continuity).
If your truck has factory cruise control, there will be a second switch on the clutch pedal for the cruise, so use the correct switch.

If (1) above shows no positive voltage with key in Start position (all the way over), then bad electrical part of the ignition switch.

 

ok.
sooooooooooooooooo

I was testing the thing wrong....duh. had meter on only the switch. Did not have it grounded on the truck. This is how we learn...right?? heh.

Couple days ago I found a $35 ignition switch on ebay and ordered it. It came today and so put it in.

With new ignition switch:
I am getting 12. (+) volts on one side.
10.4 ish volts on the other.
It is turning over consistently, though does drag every so slightly.
But overall seems to be consistently working !!!!!!!!!!

unfortunately I do not have accurate test results from the old switch because I tested it incorrectly before I took it out and read your most recent post.

 

That 10.4 volts is fine if that's measured while actually trying to start the engine (minimum is generally considered 9.6 volts while cranking).

Good; I'd say you did isolate the issue to the ignition switch.


Right - all you can yo at this point for that is measure the ohms resistance between incoming wire and the "run" wire in the "run" position, and between incoming wire and the "start" wire in the "start" position. But sounds like the replacement switch did the trick.

Was that a brand-new switch for $35?? I paid $103 at the dealer for the part in 1995 for mine, they were dealer only then, and I didn't have any Internet knowledge then.

 

http://www.ebay.com/itm/IGNITION-STARTER-SWITCH-90-93-Mazda-Pickup-B2200-B2600/302267402084?fits=Year%3A1991%7CModel%3AB2200&epid =12006570070&hash=item46608a8764:g:LfcAAOSwSlBY3CD U:sc:USPSFirstClass!11215!US!-1:rk:17f:0


Hey, Well actually I would say YOU, Cusser, isolated the problem. And thanks very much. At the very beginning you suggested this was the problem. Perhaps I tested the switch wrong then??
Anyway. Thanks much!, and thanks Grim Reaper and all for your help. Certainly would not have figured it out on my own.
and it is really nice to be able to drive my lil truck around and not worry that I can't turn it off. ….Now for the next project on it!

Hope this is the last of this issue.

Thanks thanks!!!

 

Great !

The "trick" is to diagnose the issue, and then fix or replace the bad part. One would hate to buy a new switch like this or a starter and then find a bad connection at the battery was the root cause !!!

The supplier you used lists a slightly-different switch for my 1988, at $3 less. Both this and yours are made in Taiwan, generally considered better quality than from mainland China. As an exercise, I checked O'Reilly site today for switch for mine: it was $106.99 plus tax. And I checked RockAuto for mine, $54 plus shipping. So large savings doing Internet for this part.