Jump starting

pickup
gmc

#1

what may have my son fried by reversing the polarity while jumping the battery in his 95 GMC pickup? The smaller wire coming off the + terminal was burned through,so I spliced that. The engine cranks but there is no spark.


#2

First three things tha come to mind are, anything powered off that small wire that burned through, internal components inside the distributor (do the “no-spark” test procedure from the manual) and the PCM. You do not mention if you have done a fuse check, people always say they did a fuse check.


#3

Couldve fried ANYTHING electronic.


#4

It’s at this point you hope that the protection mechanisms designed into the vehicle have saved your bacon. They’re not specifically designed to prevent damage in this situation but you can hope.

I would first check for bus voltage at the fuse box.
Bad- check the fusable links in the wiring harness.
OK- check all of the fuses.
Then check the ECM by at least seeing if it will respond to inquiry.

Hopefully, you will discover a fault by this point in the diagnosis…