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Glad2bhere · 01-28-2023, 05:24 PM

Hello!
New member here, but have found lots of useful information here in the past, including clues to the current issue.
Background: Bought this coach a year ago with only 54k miles on it and in great condition. Good maintenance records from PO including Ford reman transmission replacement at about 38k miles at a Ford dealership. Service record indicated necessary replacement as coach had been driven with parking brake on. That assembly was also replaced. Coach was in storage for most of the past 10 years before we bought it. When trans went into limp mode at about 58k miles we chalked it up to perhaps dry and cracked seals even though oil was clean and full. A local shop in Grand Forks ND rebuilt it in 3 days and got us back on the road, claiming to have put in heavier duty parts. 5k miles later we're now stuck again in OR. 2 rebuilt transmissions have been installed, rig has been given back to us 2x only to fail within 2 miles of leaving shop. This after successful test drives by the shop.
Currently no codes, MLPS, ECU, PCM replaced. We've spent days googling and have learned more about E4OD than we ever wanted to! What's curious is that there is no VSS on the rear dif and no pigtail to be found. There's a plug in the hole where it should be (photo). I have found a wire connector tucked into the frame behind the generator that has been disconnected since before purchasing the rig. Noticed while doing other maintenance (photo).
Also curious about this coiled up plug in the front driver's side next to the large fuse box/ relay panel (photo). BTW, Cruise Control has never worked. Research says Cruise Control, VSS, and ABS are all necessary for correct transmission operation. I believe I could really use a F53 wiring schematic and an E4OD wiring schematic which I haven't been able to locate if anyone has them.
Any advice appreciated!

Unplanned Tourist · 01-29-2023, 03:55 PM

Did cruise work on the test drives?

I had a strange problem once that turned out to be a blockage in a cooler line. ANY longer than 1/2 hour drive and the trans temp would spike. Cooked some seals.

GypsyR · 01-30-2023, 10:38 AM

The cruise isn't part of the deal other than it needs a VSS signal to function. Can't control vehicle speed if you don't know the vehicle speed, right? Same with the transmission. If the computer never sees any road speed it will never upshift because it doesn't know the coach is moving.
On my 1993 if I recall right the output/VSS is on the top of the adapter to the park brake assembly. A sort of flattish two wire plug. Also in the area on the frame is a tied up fuel pump three wire plug. Apparently the chassis shipped to the coach builder with a complete quite small forward fuel tank which was then replaced by the rearward big tank it has now. Standard procedure from Ford on these so they could move the chassis around the build lots I'm told.

No idea what the huge bundle of wires is. Me, I'd totally have to investigate that no matter what else. Curiosity would kill me.

GypsyR · 01-30-2023, 11:44 AM

Picture of the VSS on a 2wd like mine. Except I (we) have 4wd versions because of the parking brake assembly. Physical location is the same though. In different years the sensor would be a round assembly in the side of the tailhousing, on actual 4wd's it would be to the rear of the transfer case, and some light duty later vehicles didn't have one and instead used the rear ABS sensor on the rear differential.

Some random black wire draped over the sensor, ignore that.

Glad2bhere · 01-30-2023, 02:44 PM

Gypsy,
Thanks for this! I'll bet the random 3 wire connector with 2 wires could be that shipping fuel pump or sending unit. You're right about the VSS being on the right side of the trans and the PCM should only need one VSS input. We have about 8,000 miles on the coach since we purchased and the cruise hasn't worked. Therefore I agree that it shouldn't be part of the transmission wiring and it's not shown on the schematic I received from Ford Motorhome support today.
As for the spare harnesses, I've been hoping to find a '96 F53 bare chassis schematic to sort it from there. Best I've found so far is from factory-manuals.com. $100 for the service manual and $70 for the wiring diagrams. Haven't popped for those yet.
Thanks for the reply!