I'm having a very strange problem with my '97, fellas. My odometer is not keeping mileage in memory. It will count up while the truck is running and driving, with no issues. The distance traveled is accurate. The speedo works flawlessly. But when you turn the truck off, and then turn the key back on, the odo will have lost some or all of the mileage for that trip. (it depends on the length of the trip, if its a short trip, maybe less than 20 miles, it loses all the mileage. On longer trips, it won't lose all the miles traveled, but it will read lower after turning the key off and on again.)

I have done a lot of reading on the subject of PSOM's now, and it turns out that almost nobody has this problem, or probably more likely, almost nobody NOTICES this problem, since it cause no driveability concerns. But I thought that my problem must be in the PSOM somewhere. I called up a place that rebuilds them, "clusterfix.net", and he has seen this exact problem once before. He never figured it out what component of the PSOM causes it, but he had verified it in bench testing that the issue is in the PSOM. So he recommended I verify the "always hot" lead to the PSOM, and maybe try a junkyard unit.

So, I have verified power to the connector on the PSOM, its good. I went and got a junkyard PSOM from a '96 powerstroke. Exact same part number as mine. Took it for a test drive, AND THE DAM THING STILL DOESNT STORE MILES DRIVEN!

I'm perplexed... In consideration of the possibility that this junkyard unit has the same problem as my original PSOM, I plan to exchange for another one from the JY; they had a '96 gasser with an intact cluster.

Other than that, does anyone have ideas about things to check, a wiring diagram, etc? I found this diagram, but I'm pretty sure my connector had more wires in it... 1983 Ford Bronco PSOM picture | SuperMotors.net

 

Weird, this will give you a bump.

 

Yes, very strange. I'm not even sure where to start, but here is another bump.

 

Could it somehow be stuck in Trip mode?

 

That's a thought. I will check the trip odometer next time I shut it off. I believe it is behaving the same as the main odo, that is, it is losing the same number of miles as the main odo.

 

Hey mate I'm in aus and have the exact same situation. Will not count kms (metric here). You end up finding a solve for this? I've been right through my truck. Replaced everything bar the wiring harness. Mine definitely isn't stuck in trip mode. Just can't add up

 

 

Pull the cluster and clean the contacts on the back.

The keepalive voltage isn't getting there to keep the cluster's volatile memory active.