Speedometer problems--electrical???? - Ford Powerstroke Diesel Forum
User Tag List

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 26 Old 10-06-2012, 10:47 AM Thread Starter
Compression Ignition Addict
 
Woodturner Nate's Avatar
 
Join Date: Jun 2012
Location: Charlottesville
Posts: 172
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Speedometer problems--electrical????

My '96 powerstroke is having ISSUES. First off, the E4OD transmission was just rebuilt after deciding it didn't want to go forward. Apparently some gear cylinder had a hairline crack. The garage I was dealing with removed the transmission, then it went to a specialty rebuild center, then the garage put it back in. They didn't do the tranny work, in other words.

Anyway, as I'm picking up the car, I drive it down the road and immediately notice that the speedometer is freaking out--it is jiggling back and forth, in about a 20mph range, with the bottom-middle range being about where the actual speed probably is. I promptly turned around and went back to the garage. I figured the speedometer cable was loose, and found out that it isn't a cable, but a sensor on the rear differential. They said they didn't have a sensor in stock, but that it should solve the problem, and wasn't related to the transmission work. I bought that, sounded plausible to me.

I headed home from the shop, as I didn't have the option of leaving it there-I needed the truck! I just was careful with my speed and went pretty slow. I realized that the tranny was having issues keeping itself in 3rd/4th/overdrive in between 35-45mph. The VSS (variable speed sensor) problem really made sense to me, and sounded like it was the issue, as it seems that it controls the OD function of the tranny??? (I've read that somewhere here on this site). At some point the next day, as I have to get a load of firewood or risk being cold this winter, I realized that when I pushed the trip odometer button, the problem seemed to instantly vanish. The transmission shifted fine, stayed in the right gear, speedometer was smooth. Then, a couple days later, same deal. Dancing speedometer. Same fix, except that the next time it happened, the third or fourth time, the odometer button didn't seem to fix it.


I bought a new VSS and installed it; no change in the problem. I also dismantled the dash and checked that the connections were all tight as best as I am able to check-nothing is loose or obviously disconnected. I had changed some light bulbs a while back and thought that I might have loosened something, but everything appears normal. The guy at the shop where I got the part said their shop truck, a GMC, does the same thing, and it has a motorized speedometer, not unlike the Powerstroke Ford. It is clear to see when you have the dash apart and look at the circuit board.

So now I'm confused about what I do now?? Will replacing the whole gauge cluster reset my odometer ?? Not doing anything isn't an option, due to the tranny shifting funny when the speedometer is between 35-45mph. What kind of electrical problem am I missing???

1996 F250 eclb, 4x4, 7.3L PS
425,000 mi and counting
Viair 444C/6g air tank on frame, Hadley air horn, Hella auxiliary reverse light, DIY WVO conversion; Efuel, dual FuelLab FPR's, 90g RDS tank, aluminum tube-in-heater hose, hotfox heated fuel pickup, copper coil-wrapped filter, 40-plate FPHE, auxiliary coolant pump, 2000lb winch-crane bolted to the frame. Ranch hand front bumper. Big winch.
Woodturner Nate is offline  
post #2 of 26 Old 10-06-2012, 11:10 PM
Serving Our Country!
 
JSchuricht's Avatar
 
Join Date: Aug 2007
Location: Manor, TX
Posts: 2,968
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 25 Times in 24 Posts
Feedback Score: 2 reviews
The VSS sends a pulse as the teeth of the tone ring in the rear diff pass it. The signal goes to the PSOM and the RABS unit. It sounds like your PSOM has gone bad which is not uncommon. The PSOM or programable speedometer odometer is the center section of your cluster and the mileage is stored in it so when you replace it you will see the mileage of the new unit. On the plus side you can get one from just about any similar vehicle gass or diesel 150-350 and bronco. Your transmission relies on the output of the PSOM to operate properly, try not to drive it much, your transmission will go into limp mode and shift harsh or possibly break something.

JSchuricht is offline  
post #3 of 26 Old 10-07-2012, 08:09 AM Thread Starter
Compression Ignition Addict
 
Woodturner Nate's Avatar
 
Join Date: Jun 2012
Location: Charlottesville
Posts: 172
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Yeah, its been shifting hard for certain. So, basically, if I disassemble the cluster itself I can replace just the speedometer odometer? I'll have to look at it again; I couldn't figure out how to remove the front and back plate from the dash cluster when I had it completely out of the truck.

1996 F250 eclb, 4x4, 7.3L PS
425,000 mi and counting
Viair 444C/6g air tank on frame, Hadley air horn, Hella auxiliary reverse light, DIY WVO conversion; Efuel, dual FuelLab FPR's, 90g RDS tank, aluminum tube-in-heater hose, hotfox heated fuel pickup, copper coil-wrapped filter, 40-plate FPHE, auxiliary coolant pump, 2000lb winch-crane bolted to the frame. Ranch hand front bumper. Big winch.
Woodturner Nate is offline  
post #4 of 26 Old 10-07-2012, 10:47 PM
Serving Our Country!
 
JSchuricht's Avatar
 
Join Date: Aug 2007
Location: Manor, TX
Posts: 2,968
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 25 Times in 24 Posts
Feedback Score: 2 reviews
It's been a while but from what I remember you pull the cluster, remove the clear plastic on the front then just pull the gauge forward. It had around 4 tabs and a cable.

JSchuricht is offline  
post #5 of 26 Old 01-12-2013, 01:14 AM
Member
 
Ford_Iowa_Boy_7.3's Avatar
 
Join Date: Nov 2012
Posts: 38
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
I've been havin a similar problem as you described and was wondering what ended up fixin it. I also recently had a rebuilt transmission installed. Thanks!

Sent from my SCH-R530U using AutoGuide.Com Free App

Will Maddie
96 F350 7.3L
Crew Cab Long Box SRW
"Whistlin Dixie"
Ford_Iowa_Boy_7.3 is offline  
post #6 of 26 Old 01-15-2013, 07:55 PM Thread Starter
Compression Ignition Addict
 
Woodturner Nate's Avatar
 
Join Date: Jun 2012
Location: Charlottesville
Posts: 172
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
I ended up having to replace the cluster with a used part. It has a different mileage than my truck did. I just lose the honor of looking like I have nearly 400K on it. The used cluster had about 80K less miles.

1996 F250 eclb, 4x4, 7.3L PS
425,000 mi and counting
Viair 444C/6g air tank on frame, Hadley air horn, Hella auxiliary reverse light, DIY WVO conversion; Efuel, dual FuelLab FPR's, 90g RDS tank, aluminum tube-in-heater hose, hotfox heated fuel pickup, copper coil-wrapped filter, 40-plate FPHE, auxiliary coolant pump, 2000lb winch-crane bolted to the frame. Ranch hand front bumper. Big winch.
Woodturner Nate is offline  
post #7 of 26 Old 01-15-2013, 07:57 PM
Member
 
Ford_Iowa_Boy_7.3's Avatar
 
Join Date: Nov 2012
Posts: 38
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
How tricky is that and what year and model truck dashes can I use to replace it?

Sent from my SCH-R530U using AutoGuide.Com Free App

Will Maddie
96 F350 7.3L
Crew Cab Long Box SRW
"Whistlin Dixie"
Ford_Iowa_Boy_7.3 is offline  
post #8 of 26 Old 01-17-2013, 12:16 AM
Serving Our Country!
 
JSchuricht's Avatar
 
Join Date: Aug 2007
Location: Manor, TX
Posts: 2,968
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 25 Times in 24 Posts
Feedback Score: 2 reviews
The PSOM is really easy to swap. You can use one from a 150-350 or Bronco. I don't know the year that that style started but 94-97 would be a safe bet for a donor, the older stuff was mechanical and looked vary different.


Last edited by JSchuricht; 01-17-2013 at 08:57 PM.
JSchuricht is offline  
post #9 of 26 Old 01-17-2013, 12:18 AM
Member
 
Ford_Iowa_Boy_7.3's Avatar
 
Join Date: Nov 2012
Posts: 38
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Thank you sir

sent from my s3 while listenin to the sound of my turbo whistle

Will Maddie
96 F350 7.3L
Crew Cab Long Box SRW
"Whistlin Dixie"
Ford_Iowa_Boy_7.3 is offline  
post #10 of 26 Old 01-17-2013, 05:06 AM
Compression Ignition Addict
 
Join Date: Aug 2008
Location: Madison, WI
Posts: 3,856
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Thanks: 4
Thanked 126 Times in 122 Posts
Feedback Score: 0 reviews
'92-'96, or '97 F250-F350.
madpogue is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome