So i just picked up a 95 b2500,runs great for about 15 or 20 mins then dies,no cel light when i try to restart it.replace coil,coil pickup,crnk sensor,fuel pump and asd relay,found one pin on the ecu harness was causeing this so i replaced it as well,now when it dies if i grab the harness that lays on driver side of the intake i can make the cel light come on and run for a min,if i let go it dies.the weird thing is that when i move the harness it makes the ac clutch click and the od relay for the trans click?some had mentioned to check the wire from the trans back to the ecu.any have any ideas or yall think its a short in the harness?is this a common problem? Thanks in advance

 

I'm no electrical expert by any means but, if by "moving the harness" on the firewall to PCM is what causes cel to come on and run a minute/the relays to click, maybe a 'cleaning of and securing' that connection may help?... can't hurt for sure.
In some past threads guys have touted an electrical cleaner called Deoxit that is said to really clean connections well, available online,but CRC cleaner can be found most any parts house, hardware store or or walmart. Disconnect the neg. battery cable, spray the connections and lightly brush with an old tooth brush to help clean, spray it out again and let dry, dab some Dielectric grease at the connection pins and see if that helps at all... If there actually is a short, I won't be of much help but this may help rule out a dirty/bad connection and hopefully someone else will reply with some better troubleshooting advice.
I had also seen some past threads where guys had wrapped zip ties over and around the PCM and front of the connector to secure it because of a broken snap on the harness connector to keep it snug on the pcm.


Hey, gooluck in anycase and let us know how things go

 

Yeah,i pulled the ecu and layed it flat,same results,connection is all clean,i started it today and blowing a ton of black smoke(major overfuleing) this is a new problem,got it to die and no re start now.i have 2 capacitors that look as tho they have possibly leaked.think im probably gonna send it off to have the ecu rebuilt