Ok so Ive done all I can think of and searched and searched and couldn't come up with the next thing to check . So here is what I have 2000 7.3 wont start pulling codes p1280,p1000,p0603,pp1266(aftermarket security system) It has a new two new battery's, CPS and IDM. I get the wait to start light and while cranking i get no RPMs. It cranks over strong it should show RPM but it doesn't Any suggestion on what to check? I have checked all the fuses. Also I am getting a very strong smell (smell like either burning) when cranking but no smoke at all.

 

Have you tried unplugging your icp sensor and trying to start it? How's the oil level in the crankcase? How's the level of the hop res? How many miles does this truck have? Is it cold where you are? Have you checked the gpr? Does it start if plugged in?

 

I think I found my problem. I have done the mentioned above. The excursion has 120k on it and is in a heated shop temp around 70 degrees. The security code that it is showing has the engine disabled from starting. The provious owner had the column apart because of a broken ingnition switch rod. When I reassemble the column I noticed the ring that goes around the tumbler was broke. Didnt think anything of it so I ordered a new one and will be here tomarrow sometime.