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Topic: Analog Speedometer question - 1995 U300 (Read 1030 times) previous topic - next topic

Analog Speedometer question - 1995 U300

During my current trip south I noticed that my analog VDO speedometer had stopped working (both speed and odometer). After the next stop it worked normally again for a brief period. Speedometer then started reading approximately half speed or no speed.  Cruise control is working fine. I have pulled / reinstalled all the electrical connections off the back of the unit but I'm not sure where the sender connections are located on my Allison HD604 transmission. Because of the erratic performance I'm thinking that a poor electrical connection is the most likely culprit however a review of the newsgroup postings on this subject seems to indicate a high probability of a speedometer problem. Any good suggestion as to how to confirm problem area ?

Thanks to all - as usual
Jon Harris
1995 U300 Unihome
Cat 3176
The selected media item is not currently available.

Re: Analog Speedometer question - 1995 U300

Reply #1 –
Jon,

Call Joe or Steve at Instrument Exchange for help diagnosing your situation.

They are a repair station for VDO and have all the parts and knowledge you will probably need.

713.923.6104  or  800.945.GAGE
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: Analog Speedometer question - 1995 U300

Reply #2 –
Jon,

My motorhome is a 92 don't know if this will help but sending a picture of mine. I had to replace the signal generator on mine and a tang that drove the generator. If I can be of any help feel free to pm me or call 512-753-9655.

The selected media item is not currently available.
Bobby & Norma
1992 GV U280
C8.3 Cummins

Re: Analog Speedometer question - 1995 U300

Reply #3 –
Quote from: Jon H –
During my current trip south I noticed that my analog VDO speedometer had stopped working (both speed and odometer). After the next stop it worked normally again for a brief period. Speedometer then started reading approximately half speed or no speed.  Cruise control is working fine. I have pulled / reinstalled all the electrical connections off the back of the unit but I'm not sure where the sender connections are located on my Allison HD604 transmission. Because of the erratic performance I'm thinking that a poor electrical connection is the most likely culprit however a review of the newsgroup postings on this subject seems to indicate a high probability of a speedometer problem. Any good suggestion as to how to confirm problem area ?

Thanks to all - as usual

Jon ; did you figure out which it was? speedo or sender? I am having the same symptoms now on my U225.  thanks Pat
1994 u300

Re: Analog Speedometer question - 1995 U300

Reply #4 –
Not a fix, but my speedometer - not OEM but still VDO with a digital odometer that was installed about 18,000 miles prior to my buying the coach in 2011 - is erratic. It never actually stops but it varies by about 5mph so that one has to pick an average of the needle movements to use as "speed".

This is annoying but I happen to have an old Android cell phone that no longer gets service but happily acts as a GPS even without any network connection. I installed Ulysses Speedometer https://play.google.com/store/apps/details?id=com.binarytoys.speedometer&hl=en on this device and it gives me speed, time, trip distance, etc. Normally I have it on the sliding table next to the driver position but when it's cloudy or dark I set it to HUD (Heads Up Display) mode and lay it on the dashboard so it reflects in the winshield. It's pretty dim so in bright sun it's invisible but if it's cloudy or dark it's fine. The HUD only displays speed though but that's enough... and I don't have to take my eyes off the road.

The HUD option is pretty handy.

It's free but there is a "Pro" version (without the ads... which are pretty small at the bottom anyway).

Just FYI.

Craig
1993 U225 36' Unihome GV with PACBRAKE exhaust retarder, Banks Stinger and Solar Panels.
Toad: 1999 Jeep Wrangler 2-door soft-top.

"No one has ever had to evacuate a city because the solar panels broke."

Re: Analog Speedometer question - 1995 U300

Reply #5 –
thanks craig; I will get that!.

I just want to fix every single thing in my coach before I sell it, that is why the speedo fix.  Pat
1994 u300

Re: Analog Speedometer question - 1995 U300

Reply #6 –
I had a similar problem several years ago that was very difficult to pin down.  I took the speedo in to Houston Instrument Exchange and they were very helpful in bench testing the unit for several hours at no charge.  It checked out fine.  They had several other suggestions for checking the sending unit but nothing helped. I took the coach to Stewart & Stevenson where they tried plugging in a new computer module.  That didn't work either but in the process one of their techs ruined my front door hinge because he didn't know how to release the hinge latch so he forced it closed.  I had crawl through a window and disassemble the door handle mechanism from this inside.  Anyway, a couple of hundred $ in diagnostic time, a broken door and they couldn't find the problem either.  I lived with the problem until another mechanic working on something else discovered that something was wired wrong at my isolator block and relays.  Apparently it was indirectly backfeeding some electrical signals that were confusing the speedo sending unit.  Corrected the wiring and it's been fine ever since.  Not sure exactly what it was though.

Re: Analog Speedometer question - 1995 U300

Reply #7 –
I sent mine to Instrument Exchange (Rudy's suggestion) and they advised that it was inop and not repairable. Replaced it with a digital unit.
Jon Harris
1995 U300 Unihome
Cat 3176
The selected media item is not currently available.

Re: Analog Speedometer question - 1995 U300

Reply #8 –
Quote from: Jon H –
Replaced it with a digital unit.

Jon,
 
That sounds very interesting.
What did you get?
Where did you get it?
How did you install it?
Pictures please.
 
If you have written it up, let me know and I will look for it.
 
Thanks,
 
Trent
Trent and Jean Eyler
2000  U295  4003  WTFE  ISC  350
Build#5603 MC#17385

Re: Analog Speedometer question - 1995 U300

Reply #9 –
I just took this pic of the sender or what is it? is one a trans temp gauge and the other the speedo sender? I just don't know which is which, maybe someone here can help? 1992 5.9 cummins and a 4 speed Allison if that helps. thanks!
1994 u300

Re: Analog Speedometer question - 1995 U300

Reply #10 –
Quote from: poolenglish –
I just took this pic of the sender or what is it? is one a trans temp gauge and the other the speedo sender? I just don't know which is which, maybe someone here can help? 1992 5.9 cummins and a 4 speed Allison if that helps. thanks!

It looks a lot like the cruise control signal generator shown here:  Cruise Control Signal Generator