truck won't start volvo 2004 help pablo!

I was just going to say it is your ignition switch.

 

Check the fuse back at the battery box again, could have shorted out while changing the switch.

 

How do I delete a reply?

 

I would have someone hook up to the computer port and see if there are any fault codes or anything else that looks out of the ordinary first. Does the engine just spin over and over by starter without firing, or does it start for a moment and then die? The fuse being blown should have spared the ecu, also, the $250 seems really low for an ecu and programing, I would have guessed closer to $2500. Just shorting the hot cable to the frame rail should not result in toasting the ecu, are you sure that the ignition switch is wired back in exactly as it should be, it sounds more like, (if the engine is not firing at all), the ignition switch is not providing power to the ecu., If however the engine does fire and run for a moment, depending on how you have the ecu programmed, it could be low on water, not getting oild pressure, etc...etc..

 

This is all assuming that the truck has fuel in the tanks, and that it hasn't sat for a while and the fuel leaked down, so that it would need to be reprimed.

 

If it fires up, then stalls, I would call a mechanic and see if he can tell you the meaning of the fault code. My cat did this and it was the first time I had ever went through this. I called CAT and he told me how to toggle the cruise control switchs and count the number of times that the yellow light flashed, after doing this he said that my water level was low, I filled the expansion chamber and never had any more problems. I had forgotten having it set up so that the engine won't run if the water is low, if the engine temperature is high, or if the oil pressure drops,...etc..etc...
What happened to me was that over the years the plastic expansion chamber discolored so that you could not see the exact level of the water, it looked like it was full, but it was just a discoloration where the water level had been for years, when I pulled the cap and looked inside I could readily see that it was low, sssooo change in the pretrip was in order. Check it out, but if it starts and runs, not being there to see or hear anything, my first guess would be something like this, safety shut down.