I'm new to this site, on Christmas eve my 2003 Caravan stalled and would no longer start, you can hear the starter relay doing it's job but still won't start. The battery checked out good I took the starter out and tested out good as well and, checked continuity between starter relay pin 85 to PCM pin 31 good there checked pin 87 from starter relay to yellow and grey starter wire good there too. But no 12 volts on yellow and grey starter wire when ignition key is turned. Does this mean my PCM is bad, I just want to make sure I diagnosed this correctly any help would be appreciated.

 

No. Not the PCM though I'll never say never with these vans. The key is you hear the starter relay clicking. The only way it can click is if the PCM is supplying the ground at the relay coil - contact #85. Re-verify the starter relay is clicking. Feel it. Sometimes a neighboring relay in the box can make you think the starter relay is clicking.

It appears the control side of the relay (ign switch, relay coil, PCM, TRS) is working. To verify the output side (relay contacts, battery, starter) are working, remove the relay and jumper contacts #30 and #87. The starter should rotate right away. No need to turn the key. No go? Check the 40 amp fuse. Swap the relay with another relay with the same part number. Check for 12vdc at contact #30. Check for 12vdc at the larger connection at the starter.

Did the battery pass a load test? Were the battery and starter connections clean and tight? Did you try jump starting it? How was the starter tested? Always disconnect the battery before disconnecting the PCM.

 

I swapped the relay with the windshiled wiper relay right next to it they have the same part number and no change. I do have 12 volts on the big starter wire. Today I applied +12 volts to pin 87 and it would crank but not start even with the key in the ignition on run. I did however forget to check continuity between pin 30 and the positive battery cable and also to check if I do have 12 volts on pin 30 as well which would take me to the 40 amp fuse which I totally over looked. Thanks for the help I will let you know what I find.

 

I forgot to mention that I had the battery tested and they said it was good just a little low and had it charged, tried my jump starter to see if it would start with no change. Checked tightness of all battery cables and wires going to starter they were good, took the starter out and had a mechanic bench test it and it looked like it works fine. Put it all back in then jumped it from pin 87 straight with +12 volts it cranked but no start.

 

Today I checked operation of the starter relay again what i thought i heard clicking was actually the accesory relay, then with the key on pin 30 to ground had 12 volts; pin 86 to ground had 3.2 millivolts. Is the PCM not allowing the starter relay to connect to ground.