1985 Dodge Ramcharger ignition system

A 4 prong ecm has a single ballast resistor while a 5 prong has a dual ballast resistor. The car shold not run with the ecm unplugged. In order to check the control unit you need a volt/ohm meter. You should have 10-12 volts on both sides of ht ecoil if nt there is either a poor connection between teh coil and unit or a bad ground between the unitcase and firewall. If you have normal voltage at teh positive side, but low voltage 6-7.6 volts at the negative terminal then teh there is grounded wirig between coil and unit or a defective unit. It should not need to be rewired if it has never been messed with in the first place. Also it is VERY important that the air gap on the pick up coil in the distributor be set at.008"-.010" this has to be done with a non-magnetic feeler guage.