[Tyler Stache]

So heres the story i put my truck in the shop for a oil cooler rebuild/reseal and a coolant leak and battery change.... With that being said i have a late 99 7.3L powerstroke it also has a remote start the avital 4000X... shop got the truck into the shop replaced batteries went to go start it it just cranks they checked for codes and it shows codes for glow plugs, injectors and just about everything which says to me and the shop owner SECUIRTY SYSTEM!! the Avital 4000XL no one seems to know a damn thing about it so we took the battery cables off let it sit for 3-4 minutes then put them back on Negative then positives and still cranking fast but no start... doesnt show oil pressure or crank rpm which 1 week ago it ran perfectly fine no misses no smoke i dont even think i saw... theres fuel in the fuel bowl and the security light is not coming on which is weird... anyone know what it could be?? Basically the shop said theres no power going to PCM i believe and no avital techs know **** about it so now im irritated and putting more money into something that should be simple to fix.... no blown fuses or anything i have over 5k into this dang truck in 2 weeks now....

 

[klhansen]

Did you check both fuse boxes? There's one under the hood and another under the dash. A fuse tester or meter should be used, as they can sometimes fool a visual test.

If the PCM isn't getting power, you should check the fuel heater fuse that also powers the PCM power relay control circuit. It's a 5A fuse under the dash. If it's blown, unplug the fuel heater connection on the back of the fuel filter bowl, replace the fuse and try again. You might also swap the PCM power relay with a non-essential one like the heater fan motor relay, if the fuel heater fuse doesn't fix it.

If you crank it long enough, the oil pressure gauge should show something, although it may not be powered either. It's just a switch on top of the HPOP reservoir that sends a go-no-go signal to the "gauge" (actually just an idiot light disguised as a gauge).

It's also possible that the Low Pressure Oil Pump lost it's prime, since they had the oil cooler off. Pull the plug on top of the HPOP reservoir and see if there's oil within an inch of the top. If not, fill that with engine oil and try again. If you aren't getting oil to the injectors, it will never run. Filling the reservoir will give the HPOP something to use until the LPOP regains its prime and starts pumping oil again.

It could also be that your security system has reset with the loss of power (battery change) and isn't letting things power up. I am not familiar with how any of them work, so it might be interrupting power to the PCM until you get it back on line and give it the right "password".