95 Sonoma, engine intermittently dies

150K miles, 4.3L V6, automatic. Have had this problem since I bought the truck, 6 wks ago.

Engine will die while driving then immediately restart (Idiot lights come on,then off). Sometimes repeats within 1-2 minutes, then may run fine for a week or so. Will also die upon startup-but will restart if it sets for a minute. Doesn’t matter if engine is hot or cold- no rhyme or reason.

Otherwise the truck runs great, no misses, good power, etc.

Thanks for any help!


There are many possibilities; but, I think that a break is occurring in the RUN circuit. The break is most likely in some contact in some switch; or, if a relay, the power holding the relay’s pull-in coil in and releasing the contacts from contact.
An electrician could check the RUN circuit by setting his voltmeter lead on ground, and the other probe on the circuit. Then, as the ignition key is repeatedly turned to RUN and off, the voltage is observed. Once when the voltage drops (in RUN), repeating further along the circuit, and actuating the ignition key OFF to RUN, repeatedly will (eventually) find the bad contact.