Electrical question. Crank no start no fuel no spark truck will not read rpm . 1998 Dodge Ram 1500 5.9 so the truck ran like **** a couple weeks back remedied they problem was fuel sync camshaft posistion sensor new sensor still tests good . But now after 2 plus weeks of normal runnning. The truck is bricked for lack of better term. Crank no start. Fuel pump does not run tested good in all aspects.(fuse harness relay even dropped tank and it’s a oem good model) when you turn the key no prime. No ignition either good ground etc good coil. Truck dosent want to run at all. Have tried 3 different pcm all with similar results same problems so I’m to the point of ruling that out. Hand cleaned every connector and ground. ASD relay is known good aswell. I have also tried all 3 of my crank sensors I had as extra Any help is appreciated. I have a snap on mt-2500 a graphing scanner and the obd 2 port does not power them in the “run posistion” but it does in crank and off. Again I seriously appreciate any help.

 

The first place to go is to check all your powers and grounds. Check, especially for any 'potential difference' between battery ground and frame and engine grounds. Then, if you don't have a 'breakout box, try bypassing the ignition switch.
Good luck, we're all counting on you!

 

any tips on the ignition bypass? Thanks

 

If you aren't getting fuel pump prime at initial key on, there is a definite problem there. Is the PCM trying to control the fuel pump relay? Do the ASD and fuel pump relays have power in the appropriate spots? (pin 30 should always be hot, pin 85 should be hot with ignition on.)

 

will definetly check those pins when I get off work here.

 

I assume you checked ALL the fuses? When you turn the key on does the check engine light come on?

 

You'll need a wiring diagram. As I'm sure you're aware, the starting circuit is only part of the ignition switch. Unplug the ignition switch or back probe it n I can guarantee that there's some kind of power maintenance for the rest of the pick up to run on during normal operations. Since you have OBD in 'certain' ignition key switch modes, then if you short together those related contacts...and if that's you're problem, you'll have OBD info available all the time.