Loss of power

[subford]

You need to drive it with a fuel pressure gauge hooked to the fuel rail. You should get about 30-34psi at idle and around 40psi at WOT.
If you can not get it up to around 40psi at WOT then I would think you have a bad fuel pump in the fuel tank or low voltage to it. You can check the voltage at the fuel shut off inertia switch.

I do not think that this related to the speedometer however.
If both fuses are good with power on both sides that feed the PSOM I would think maybe you have a bad PSOM.
The VSS & wiring should be good or you would also have problems with the shifting of the E4OD transmission.

[ARFFMAN]

Isl this the correct PSOM for my 1994 MH- 92-96 FORD F SERIES TRUCK AND BRONCO PSOM SPEEDOMETER 1992, 1993, 1994 95 96

[subford]

That is a photo of a speedometer head and not a PSOM.
The one in the photo above is from a F-150 - F350 truck as the numbers are ending in zeros. The ones for E-series and the F-53 have numbers ending in fives as in 85.
Other than that, that head would work but the PSOM information from your old PSOM would still have to be copied from the old to the new PSOM.

The PSOM is mounted on the back of the speedometer head with three screws. The LCD odometer read out is plugged into the PSOM and it looks like there is an odometer LCD read out in the photo is there.

There is a EEPROM on the PSOM board that holds the mileage, rear end calibration information, if it is English or Mertic read out and so on.

You could use the PSOM board off the back of that speedometer head and put it on yours but first you would have to copy all the information out of your old EEPROM first and copy it into the new EEPROM so it will display the miles you have on your F53 and the other information in it so it would work right and have your legal miles on the odometer LCD read out. It is not hard to copy the information from one EEPROM to another.

Also your old speedometer head or the odometer LCD display could have shorted and took out the PSOM.

The PSOM location:


The PSOM mounted on a speedometer head:


The PSOM board:


The speedometer for you F53:


/

[ARFFMAN]

Thanks for the info. I call RT Grim Electronics today and spoke with them, they sent me some info. on PSOM and VSS to read up on system. If I want to sent them the PSOM they rebuild it for $250.00. Does that sound about right. IIs there any other things I need to look at before dealing with removing PSOM.

[ARFFMAN]

Another advantage to rebuilding PSOM/Speedometer head is it will be as new and odometer will be at the correct miles on my MH

[subford]

Originally Posted by ARFFMAN

Thanks for the info. I call RT Grim Electronics today and spoke with them, they sent me some info. on PSOM and VSS to read up on system. If I want to sent them the PSOM they rebuild it for $250.00. Does that sound about right. IIs there any other things I need to look at before dealing with removing PSOM.

I do not think they will rebuild a PSOM. I think they will just copy the information from your old EEPROM to the EEPROM that they got from a salvage yard for maybe $15.00. All PSOM boards are the same from 1992-1996 for F & E series trucks/vans and the F53 through 1998.

There is nothing to rebuild on the PSOM board. They could replace the caps but I would not think they would do anything else. There is no way they would rewind the stepper motor in the speedometer head.

I think the $250.00 is about what most of those places are charging but I do not know why they charge that much for one minute of copying.
The equipment to copy only cost about $50.00 on ebay.