99 F250 LD 3V Ref Volts at DPFE
 

Just checking only reason that this can have less than 5V at bottom terminal on plug is problem in wiring harness or PCM? I have been having issues with the fuse box in cab ie; lights in dash on and off,wipers working intermittently, 4x4 in and out sometimes. Usually this other stuff I can push on fuses and they will come back on. If any one has worked with this let me know were you started and what the outcome was thanks alot

List your major issues seperately and not run them all togather.
If the DPFE has a fault, the PCM will detect it from the test routines the PCM has for that system.

So are you saying the 5v at refrence wire can be changed by pcm or can't?

The 5 volt supply is shared by about 10 other sensors.
The 5 volt supply comes from the PCM as a special isolated supply (off/above normal ground) with it's own + and - terminals.
If you measure this voltage referenced to normal ground, an incorrect reading is likely.
You must measure accross the + to the - return lead.
The neg return in not at chassis ground.
A low, grounded or open +5 from the PCM will mess up a lot of other functions as well, so be sure you are measuring it correctly.
Otherwise it is nearly meaningless to try to measure DPFE output because it is dependent on input pressure from the exhaust tubes.
Only reliable ways to test is to apply differencial pressure on the tubes for testing it's output or using a high end scanner to look at the program response to it's operation under driving conditions that causes one of the test routines to be called up or driving in OD when the EGR system is called to operate..
At this point I have no way to even guess what your issue is so just gave you some background on how things work.

ok tonight Ill remeasure to its own ground. Most of the testing I did was to the engine so I'll redo it and see what it is. Thank You