To be upfront I posted about this on OBS Revolution and still do not have this sorted out.

I have a 92 5.8 4x4 with an E40D with approx. 145K now.

When I started it up this morning, the odometer and speedometer quite while leaving my drive way. When I stopped at the end of my drive way, both came back on for a second then they both quit again. I stopped and restarted my truck but nothing changed. Shifts are rough especially from first to second and back down. I think I smelled a burnt smell when this happened. (May have been a soggy half smoked cigar in the door pocket, see recent history below)

Recent History. Went off-roading Friday and Saturday on the Outer Banks (around Cape Hatteras). Unfortunately, Saturday morning I got into deep brackish (mostly salt) water. Drove around the rest of Saturday and came back Sunday. Sunday I power washed under my truck and washed the whole thing. I made sure to take the water hose and rinse out my door jams (this causes water to get inside my truck at the top of the door jam hence water in the door pocket.

Symtoms, No Speedo, No Odo. Extremely hard shifts. Cruise Control will not set.

No fuses are blown, checked #8, #15, and #18 specifically then checked them all, interior/exterior visually. No luck on blown fuses.

Checked my RABS sensor by doing the following. I noticed a worn spot on the harness. The wiring its self appeared fine so I stopped myself from messing with that area yet. The sensor is Motorcraft and less than 12 months or 12K miles old. I unplugged it and turned the ignition on, then my RABS light came on. Plugged it back in and the RABS light went out so I assume I do not have a short in the wiring there.

The Facebook group thinks (after checking some of the things above) I may have a blown PSOM. Is this part replaceable/can I replace it and keep my original mileage?. I have a couple extras I could test. I took my PSOM out of my original cluster and swapped it to my new cluster with a tachometer around July.

 

My OD seems to turn on and off normally

 

Could be a failed PSOM, easy to test if you have a spare.

 

Ill give a try this evening but this does involve cleaning up my shet to get to my spare crap and messing with that POS Dorman replacement headlamp switch knop which does not go on and off properly to save it's life.

 

If it is isolated by replacing my PSOM how do I go about getting my PSOM repaired or a new/replacement one to show the correct mileage for my pickup? Is this afforadable or does one part replacement just destroy the value of my vehicle. This would mean the mileage shown is incorrect.

 

You can copy the mileage and tire set up with the number of changes from the original PSOM to the replacement PSOM with an EEPROM burner.
Instructions come with the burner.

Example Instructions.
http://www.sofi-tech.com/upload/prod..._manual_en.pdf

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Mine goes off and on sometimes Sometimes the needle gets pegged all the way to the right. I just tap on the face (the clear plastic) and it comes back on and the needle will pop back to whatever speed I'm doing.

 

More than likely a loose component on the PSOM board.

 

Your link did not work for me but after googling EEPROM burner it looks like a nightmare to me.

 

The PSOM was/is the problem. The unit burnt one of the 3 leads from the Motorola component by where the harness plugs in at. With the amount of board that is burnt around it I do not if it is salvageable, at least not by myself. My replacement seems to work fine minus the 212,000 mile reading and it not being calibrated to my tire size and gear ratio says 55 when I'm going about 62-63ish.

 

You can still get the mileage off the old one.
You can program the one that is in it for your tire size.

 

 

Does anyone know where I can purchase a new 5101fb transistor? I have a friend who can replace it. I'd rather not install another 20+ year old one if a new one can be procurred at a reasonable price.

 

Gave up on finding a new transistor and my buddy says the board is toasted underneath so swapping the transistor from the replacement to the orginial is a no go. Once again I cannot open the link that subford posted but I do not see anyway to lift the chips from one board to another to use one of these EEPROM burners. Help is there any method to change the mileage reading from 200K somthing to my 145448? I realize there is some legality to my question. PM me as required. The local ford dealers say they no longer have equipment to do this.

 

You do not lift the EEPROM chip from one board to copy the mileage and the board is not powered up while copying. The rest of the board can be burned up also.
I do not know why the link does not work for you as it does for me.
Here is the PDF pointed to for the link above attached.