1998 Dodge Caravan "Run" fuse pops.

GONZO77

MEMBER
1998 DODGE CARAVAN
6 CYL
FWD
AUTOMATIC
140,000 MILES

The vehicle hessitated and quit running. Dounloaded the codes and they indicated missfires on cylinders 3 and 6. Also found the RUN fuse blown. Replaced the fuse and disconnected the primary coil connector and cranked the engine several seconds, this did not pop the fuse. Reinstalled the coil primary wires connector and the engine started for about 5 seconds before the fuse poped and the engine quit. Read the primary from B+ to the other three terminals and they all read 0 ohms, two of the secondary coils read 24.4K and 24.8K ohms while the last one (for cyl 3 and 6) read open. Bought a new coil, installed it and it started right up, but it ran roughfor about a minute (definitely not running on all six cylinders) then it quit again. Read the NEW coil resistance and found the same problem. Read the primary from B+ to the other three terminals and they all read 0 ohms, two of the secondary coils read 24.4K and 24.8K ohms while the last one (for cyl 3 and 6) read open. All the chilton dagram shows is the primary wires comming from the computer. But the chilton manual does not say how to check the ASD (Automatic Shut Down) Relay nor the crank and camshafts sensors. Please help

1 Reply

KHLOW2008

MECHANIC
41,814 POSTS

Hi Gonzo77,

The main function of the ASD is to provide battery voltage to the fuel injectors, generator, ignition ciol(s) and heater on upstream and downstream O2 sensors.

PCM monitors crankshaft and camshaft sensors input signals to determine engine speed and ignition timing.
If input signals are recieved, PCM grounds the coil circuit of the relay to provide contact to deliver power supply.
If signals are not received, the PCM will not complete the circuit for power supply.
If ASD relay is energized but no 12 v input signal is recieved by the PCM, a DTC will be stored in PCM.

What you are experiencing should be shorting of a component related to the RUN fuse.