2003 thomas saf t liner wont run now.

[aridgedell]

Engine is the cummins 24v. It has always fired right up as soon as it spins over half a turn but no it just spins and spins and wont run. The wait to start and some other lights always used to come on then go out before i would start it, but now none of that comes on when i turn the key on. All the other dash lights and everything seem to work fine. Im not really sure what to look at. I briefly looked at the electrical compartment outside the bus and nothing seems out of place, no signs of rodents or anything.

 

[magnakansas]

no lights is a clue

you have lost electrical somewhere.... call if you have time. I'll try to give a clue at some of the kinds of stuff to look for..

785 207 7600

william

 

[aridgedell]

Thanks for the help william, i checked all the fuses I can find so far and all seems to be well. I looked at the wires going to the ecm that is mounted to the side of the engine and dont see anything out of place there. I found some relays and a fuse box next to the transmission fuse box that I assume is for the ecm and related parts. I think these are circuit breakers and there wasn't enough room to probe the bottom of them with a test light but they all ohm out good. I am getting power to both sides of the large circuit breakers before the fuse box pictured. I guess I have to remove the transmission fuse box to access these relays that seem to be behind it. Anyone have any diagrams of the engine wiring to help me diagnose?

 

[BlackJohn]

Just for starters, in pic 2 there is a lot of corrosion on the connections, enough for gremlins to show up.


John

 

[aridgedell]

Well after checking everything I can think of today, I feel like I have it narrowed down to either a bad ecm or a bad connection at the ecm. All fuses I can find test good with key on and a test light. I followed the wires from the battery to just before the ecm and found no signs of damaged wires. I found a diagam for a '98 cummins, of the pin locations for the ecm and all the wires that should have battery postive, battery negative, and key on, do when I test them with the ecm unplugged. I found a little gunk on the pins of the ecm, on the side where the main power and grounds are. I went ahead and pulled the ecm all the way off. If cleaning the electrical connections of the ecm and harness doesnt work I guess I'll see if I can find a replacement. If anyone has any other ideas please let me know. The first picture is the side that looks good the second has some gunk on it, not sure if it is corroded or what.

 

[aridgedell]

I took the ecm to a cummins dealer and they confirmed it was bad. I sent it off to be repaired but the ecm repair company said it could not be repaired. I bought a remanufactured ecm from them and the bus fired right up. I need to replace the battery now because it is pretty weak although it will still start the bus. Hope this helps someone.

 

[CHEESE_WAGON]

Cummins seems to be prone to ECU / PCM failures as of late.... I hear they're getting to be common in RAM trucks.

 

[jnrinkhoff]

Engine is the cummins 24v. It has always fired right up as soon as it spins over half a turn but no it just spins and spins and wont run. The wait to start and some other lights always used to come on then go out before i would start it, but now none of that comes on when i turn the key on. All the other dash lights and everything seem to work fine. Im not really sure what to look at. I briefly looked at the electrical compartment outside the bus and nothing seems out of place, no signs of rodents or anything.

We're having the same issue w/ our 2003 Saf-T-Liner, Cummins 24v. One morning it was slow to start, the Wait To Start light didn't come on. It did finally start and idled for a few minutes before I ran it up the road and it shut off. Haven't been able to start since. It cranks but won't start.

Where is the ECM mounted?

I don't have home internet...you could call if you like. 724-677-2874 Ask for Joe.

 

[jnrinkhoff]

Ok. Found the ECM...gonna take a look at it. We're waiting for an ignition to come in 'cause we know THAT needs replaced. Where did you get your remanufactured ECM and how much was it?

 

[aridgedell]

Ok. Found the ECM...gonna take a look at it. We're waiting for an ignition to come in 'cause we know THAT needs replaced. Where did you get your remanufactured ECM and how much was it?

Sorry I just saw it, I dont get on here very much, I tried looking but I dont remember the site, it was somewhere online that repaires them. I think it was about $700. Have you made any progress yet?

 

[jnrinkhoff]

Not yet...took it to Cummins who said it was at least communicating w/ their system but couldn't tell us if it was faulty or not. :/ Several other mechanics have said though that they believe the ecm is the issue

Thanks for the info!

 

[jnrinkhoff]

So....we replaced the wire that goes from ignition fuse to the A1 connector...#99. The Cummins dash lights all came on, the bus fired up, ran it about 12.5 miles and it ran great.

Then, took it out a few days later. Shut down on us several times. We thought the ignition (which we had replaced) might have had a loose connection. Pushed the plug in better and it ran. Again, took it up the road, was fine. Come out to start it today and it's having fits again.