Hi, so new to the forum but not new to fords or mechanics. I’ve got a really clean, low miles 97 7.3, rust free which is a unicorn in the great white north of Canada. Truck is my summer show and shine daily, parked it for the winter, was running good fires every time but needed a ICP and a CPS, replaced those, then went to start the WTS wouldn’t come on, so I replaced fuse 22 plus all the fuses and relays under the hood, still nothing, tested my electrical, my blower motor, interior lights, horn, radio all in working order. When I go to start the truck does crank over nicely no issues just no WTS, tach won’t move even though the CPS has been replaced, turns over like normal just won’t fire, it’s in a decent climate, stored right, batteries are good, terminals are good. Mice did not get in, truck never had any problems like this before no history of electrical issues, im stumped, it was fine before now it’s not, I suspect it’s somehow related to the PCM or wiring, did I overlook something? I normally deal with older gas bots (carb, minimal electronics) even then a 7.3 is not a computer powered machine compared to a more modern truck, am I right in suspecting the wiring or PCM, any little tricks, hopeful it doesn’t translate to full PCM swap
also I did unplug the fuel bowl heater made no difference

 

Did you try swapping the old one back in?

double check the plug and look for any chaffing or exposed wires

 

old cps was worn right out was NFG it didn’t seem to have any exposed wires worth a second look

 

Ok so here’s an update: my cps and wiring is good, then I plugged in a OBD II reader, It did not work at all. It failed to connect never worked once I tried numerous times no go, so just for laughs. I tried it on a couple other vehicles, and it worked. Did a little more digging around and diagnostics it looks like my PCM has failed So has anyone had luck in the past with rebuilt PCM’s or are you better to buy a new one and if so, which? My PCM was tuned but it was a number of years ago probably somewhere around 25 years ago when my uncle had the truck so I don’t know the exact tune or details, obviously tech has evolved since then, so I don’t want to downgrade to a stock tune PCM,

 

Lots of repair shops out there
Some can tune them
If you dont know the tune, how will they sing it?

Start listing all your mods and someone here will chime in