5.9Excursion

OK, I have a stumbling issue everytime I start the Excursion. Always been there, cold weather is alittle more evident than when it is warm. Turn key on, turn to start, fires off like it should, let key go back to the run position, and sometimes it will die.

I'm still waiting on a new FCA to install (so that may be the problem), but I think that the time the key spends between the START and RUN position that there is no voltage to the ECM and causes it to stumble.

I have not verified that the voltage is not continuous between these positions yet and was wondering if anyone else has any idea?

I have a fix if the voltage is the problem using a latching relay, but not sure yet.

Thinking about this while I type, my rail pressure gauge is powered off the same circuit as my ECM, and it doesn't display pressure while I am cranking...

I wonder if my ECM has power while I'm cranking right now?

I know when my engine was on the stand, I powered the ECM with one switch, and barely touched the starter button, fired up like a champ every time...

Aggie007

The ECM has two wires that go directly to the battery terminals for both the positive and negative.

There is a ignition on wire which that needs to be wired to the ECM. The Ford wire is the big red wire with a green stripe. It is the wire that fed the coil on plugs. On my '04 Cummins I hooked it to a grey/pink (fused ignition switch output) wire. I'll double check to be sure when I get home.

The starter should be directly wired to the battery. The smaller wire to the starter comes from the starter relay that the alternator is hooked up to. Make sure the wires are on the correct poles on the relay.

5.9Excursion

That all sounds correct. And the old wire that used to power the coils would need to be hot during cranking (for a gas engine). So that shouldn't be the problem.

Maybe tonight I will try this:

I'll provide 12V to the ECM (direct), then start it a few times and see if it stumbles. This would bypass the RUN START switch for ECM power.

Aggie007

Your ignition cylinder that you put your key it could also be worn out, but I would check everything else first. If I remember correctly, I read something about your truck dying before, that you were blowing a fuse, so you wired the starter relay on a different circuit. I did not have this problem. Maybe you have a bad connection somewhere.

5.9Excursion

I had an issue that I tried to use the ford wiring to drive the cummins starter relay (blew a fuse one time after a few weeks of driving). So I put a relay in between. This is only for the starter relay though...

Aggie007

I upgraded the cable size to 0 gauge for the starter and alternator, but didn't change the wiring layout, so I am using the Ford starter switch (relay) on the passenger firewall, and did not use any dodge components.

So I have a direct 0 gauge cable from battery 1 to the starter. Then from battery 2 I have a 0 gauge cable running to the starter switch (relay) then to the alternator. There is one wire, I used 10 gauge I think, from the starter switch (relay) to the starter.

Did you run ground cables to from the batteries to the engine block, and from the batteries to the cab?

5.9Excursion

Yes, ground from battery to block. Smaller one to body, I still need some more (frame).

I removed the ford starter solenoid from the pass side completely. I just used the little wire that activated it. Probably why you didn't have a fuse issue. Also, I used the dodge battery cable from the battery to the starter.