Clean all the ground connections...over the years, these connections corrode and sometimes develop total resistance. The wiring diagram in the appropriate shop manual will help you locate all of them. I cringe every time I think about all the $ my son and I put into his Jeep trying to fix a rough running engine...I finally checked the ground strap that connected the engine block to the firewall...the connection was covered with white fuzz with enough resistance to make the engine computer malfunction. Now, I check the grounds first. Phil Brust Jefferson GA 73 & 82 Imperial