Does anyone know how to test an Ignition control unit to see if it still works? I disconnected mine and then reconnected it the same way and it started smoking!! Possibly a short somewhere? I'm confused!

79 - 245

Far as I know, your 79 ignition module amplifies the pulses from the reluctor in the distributor and drives the coil (grounds the coil minus just as points used to) with a transistor. The unit is fairly trouble free. Because it is generally so reliable, there should be many Bosch modules available from wrecks.

Testing it would just involve connecting it in the car as it should be, cranking and observing spark at a plug. The only way I could think of letting the smoke out of it would be connecting the coil terminal to the wrong side of the coil - effectively running 12V ignition to terminal 1 or the wire that goes to terminal 1 from the Bosch module.

You don't say what led you to disconnect it in the first place. Withholding clues, move 3 squares backward and forfeit your turn;-)
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Art Benstein near Baltimore

You guessed it. I was a fool and after testing the coil and coil ballast I did the ol' switcharoo with a couple wires on accident. I didn't think anything of it until I was looking at the icu wondering what it was (I cant seem to find any record of it in my chilton manual) I touched the winshield pump and my wipers turned on and fluid started squirting. Then the smoke... I thought I destroyed everything but after the coil had the proper wires in the right places everything works fine. Stupidity is going to be the death of me one of these days.

Not your fault. Chiltons manual makes you think they've got it covered, but really it applies to the 65-75-85-90 Volvo 120-140-240-740-940 and then some. Just the front cover changes. But "testing" components is the best way to learn anything for good. Knowledge like that you never forget. Look for Haynes, or Bentley for starters-- you might wind up collecting Volvo books.
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Art Benstein near Baltimore