Sure do like to spread your questions around... Why not just ask them in one place...?

And no, there is no bench test that I am aware of for the ignition switch.

 

Ok, I installed a new ignition switch drove approx 25 miles and the Blazer stalled out again in traffic. No chugging, bucking or warning. It just quits and the dash lights go on.What would be the next part to replace in the process of elimination? All ideas, comments and suggestions greatly appreciated. Thanks. Skoot61

 

I had to resort to the dealer to troubleshoot this stalling problem further. The findings were: shorted oil switch - $58.28
fuel pump relay faulty - $38.49
fuel pump motor (binding when hot) - $497.58
environmental fees & shop supplies -$22.29
labor - $420.00
$1036.87 total

I had just replaced the fuel pump in April ...less than 1500 miles ago and now I have a new one again.

I added all my repair slips up since 12/1/06- total miles drivenfrom that time till today = 17,023

Transmission - 1836.00
Alternator -98.00
Radiator -178.00
Heater core -82.00
Multi-function switch -150.00
Wiper motor pulse circuit board -30.00
Head gasket replacement -648.00 (450.00 labor 198 parts)
Water pump replacement -183.00 (1/2 price from original quote)
Differential & transfer case replacement -
4x4 switch - oil change - fix door hinge -1361.00
New gas tank - Carter fuel pump, fuel lines & filter -1115.94
Basic Tune-Up -300.00
Ignition Module -132.00
Ignition Switch -98.00
2nd AC-Delco fuel pump install -1036.00 (less than 3 months after above install)
GRAND TOTAL = $7247.00
Just something to consider before you do what I did.... keep going for the repairs hoping it will be the last one.. It never is.