2005 Kenworth w900L /Cat C-15 ,Won't start

can you borrow another ECM that is close and see if it will fire?

 

Check fuse in battery box.

 

You never done anything but change batteries? Was the battery change just routine or something lead you to it?

 

I know this may seem random but things are strange at times. Loosen steel line coming from transfer pump at filter housing. Squirt a couple of squirt of ether in intake and crank. Truck will start on either no matter if ecm is bad or not. What you are looking for is to see if you have good pressure or air in system. You should get a strong spray of fuel. If not you have lost your prime. I know there are more proper ways to do things but everyone don't own a cat toolbox. Once you verify you are primed we can work on wiring. 11/16 on fuel line by the way. Don't take it off completely but loosen enough line moves.

 

I would think that either a wire was left off or put on the wrong post. I have seen that several times in my short career. Also check the ign fuses in the fuse box. Hopefully its a positive wire on a ground that usually turns out better than ground on positive. Did you check power to ECM fuses or just verify they weren't blown? Could still be a bad connection, The starter draws a lot of juice I have seen the ECM loose power while cranking only. Most of the time they will start on ether then when you let off the key power returns and they will run. I would definitely concentrate in the battery box since it was fine till the change.

 

NO ETHER! Go back, start over, pull all cables and check them with a test light after you put them back on. Did you use any non conducting silicone on the posts? Next, reprime til your nose bleeds. Mine was the wost thing ever to get restarted if I had problems like that. I'd concentrate on KISS. Keep it simple stupid as in the Aircraft Mechanics saying. LOL.