I have a 96 2500 ram van with a bad pcm.
The check engine light does not come on when the keys it turned.
The van did run about would die after running for just a few mins.
Now it cranks but will not start.
My question is , if I buy a used PCM how importaint is it to have one programed to my VIN.
And if I buy a used PCM how do I go about having it programed to the VIN of my van?

Only the dealer or someone with a DRB-III can reprogram the VIN. But it not necessary to do it.

Why do you say the PCM is bad? Maybe it's just not getting power, or the light is burnt out?

I just bought this van so I have never had it running correctly.
At first it would run for about 30 mins. and then it would loose power and backfire thur the intake.
I check the fuel pressure and found the pressure at 50 psi when running and 15psi when loosing power and back firing. The van has 190,000 miles so I changed the fuel pump.
It then ran for about 10mins and it would just cut off, if I waited for 10 mins it would restart and run again for 5 mins and die.
I had the engine idleing for about 15 mins and the engine died and it will now not restart.

Sure it could be the PCM, but there are other possibilities as well. For example, a bad crankshaft position sensor will do exactly what you've described. Also, like I already said, the engine light could just be blown. When the engine cuts out do other things go dead as well, like dash gauges?

The gauges do not go dead, the engine just dies.
Is it possible to ohm out the crankshaft position sensor so I can tell if this is what is causing my problem?

Is it possible to ohm out the crankshaft position sensor

No it has electronics in it, you'd just have to take the chance and replace it. Most auto parts stores have them for about $45.

I will replace the crankshaft position sensor and I will let you know what happens.
Thanks for you help so far I greatly appreciate it!!

Don't thank me until I'm proven correct. :lol:

I replaced the crankshaft position sensor, and the engine still will not start.
It just cranks.

I Checked For Voltage To The Coil And Find 9.6 Volts When The Engine Is Cranking