'93 U300 speedometer

Topic: '93 U300 speedometer (Read 1284 times) previous topic - next topic

'93 U300 speedometer

February 16, 2013, 08:02:38 am

Yesterday we looked at a 1993 U300 and liked it except for one very important issue. The speedometer doesn't work. With the key off it reads 0 (like it should when it is sitting still). As soon as the key is turned on, though, the needle immediately pegs at 85 mph and stays there, no matter what the speed. Turn the key off and back to 0. I'm thinking that it is some sort of electrical problem. The owners said it has been this way for years, and they just drive by the tach. That won't pass inspection here in Missouri, so it will have to be fixed. Any suggestions?

Re: '93 U300 speedometer

Reply #1 – February 16, 2013, 08:39:06 am

Do the 93's have electronic VDO speedometer readout heads?
If so, they simply count electronic pulses and drive the needle to a proportionally correct display position.
Defaulting to an 85 MPH indicated speed when energized means the speedometer head (dash readout display unit) has failed. Normally, FT VDO's self-calibrate each time they are energized.
Remove and repair or replace.
Many good leads on repair/replace sources on this forum. Just search "speedometer" and/or "VDO" etc.

Neal

Re: '93 U300 speedometer

Reply #2 – February 16, 2013, 09:38:17 am

Quote from: Neal Pillsbury – February 16, 2013, 08:39:06 am

Do the 93's have electronic VDO speedometer readout heads?
If so, they simply count electronic pulses and drive the needle to a proportionally correct display position.
Defaulting to an 85 MPH indicated speed when energized means the speedometer head (dash readout display unit) has failed. Normally, FT VDO's self-calibrate each time they are energized.
Remove and repair or replace.
Many good leads on repair/replace sources on this forum. Just search "speedometer" and/or "VDO" etc.
Neal

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Re: '93 U300 speedometer

Reply #3 – February 16, 2013, 09:49:53 am

My 1994 U300 Detroit 6V92 does the following; When you turn on the ignition the speedometer pegs from 0 to full speed ? (85) it then returns to 0, it then registers the proper speed 0 - 85 mph. on two occasions it did not want to register the speed when I started moving, I simply stopped, turned off the engine, and re-set the ignition to "on", it worked perfectly after that. Also, I believe that my coach had a "grounding" problem and that may have contributed to my speedometer acting up... once the ground terminals were cleaned, the issue with the speedometer never occured again.

Re: '93 U300 speedometer

Reply #4 – February 16, 2013, 10:22:36 am

Thanks. We're interested in the coach, and need to have an expert check it out for us.

Assuming that the speedometer needs to be replaced, is that a do-it-yourself project, or one best left to experts?

Re: '93 U300 speedometer

Reply #5 – February 16, 2013, 12:05:34 pm

David, it's pretty much a plug and play thing.
Richard B.

Re: '93 U300 speedometer

Reply #6 – February 16, 2013, 12:07:28 pm

Thanks. That's what I was hoping. I've had a few vehicles that all projects started with "Disassemble automobile, starting with gas cap."

Re: '93 U300 speedometer

Reply #7 – February 16, 2013, 12:18:44 pm

I have a '93 Grand Villa U300 and just recently have experienced the same problem. Turning on the ignition the needle goes to 85. Going down the road the needle fluctuates 35-85 or even sometimes displays the correct speed. Its really back and forth....but I consider it no big issue. I do like it working properly, more of a nussiance than anything. The odomometer is accurate.

Until I find the solution for it I drive by the Tach or my GPS also displays the speed, so that is another option. Anyway, who speeds in their RV anyway.....forgot to mention I just had to buy a 4 new rear tires, seems I was burning too much rubber coming out of the hole and power shifting from first to second gear!!

Re: '93 U300 speedometer

Reply #8 – February 17, 2013, 09:10:58 pm

My '91 U300 when I bought it at 124k had an erratic speedometer needle. I installed a ground wire from the speedo case to one of the ground lugs. This solved the problem. The grounding of the speedometer case relies on the mounting brackets, not reliable after many years of oxidation.

Re: '93 U300 speedometer

Reply #9 – March 02, 2013, 08:46:13 am

Quote from: prfleming – February 17, 2013, 09:10:58 pm

My '91 U300 when I bought it at 124k had an erratic speedometer needle. I installed a ground wire from the speedo case to one of the ground lugs. This solved the problem. The grounding of the speedometer case relies on the mounting brackets, not reliable after many years of oxidation.

As you now know, we bought this coach, and plan to get it as soon as weather and schedules all cooperate. Since the coach is six hours away, and the present owners aren't able to do much work, what's involved in running a wire from the speedometer to a ground lug? I'm specifically wanting to know:
1. how to open the dash cover (Lee couldn't make it open the day we were there and I didn't want to try forcing anything.)
2. what size nut will I encounter at the speedometer
3. where a ground lug is located
4. about how much wire will I need

Pictures would be a help. I have no doubts that I could do this project easily once the coach is here, but I'd really like to have something working as I drive back home if at all possible. If I can't fix it while it is sitting at Weatherred's I'll just have Jo Ann drive the car ahead of me at a steady 60 mpg and I'll get a tach reading and go from that.

Someone mentioned that the electronic readout will also provide speed information. The day we were there that monitor didn't turn on. I'm wondering if there is more going on under the dash than just the speedometer not behaving. Perhaps more than one instrument has a grounding problem.

Re: '93 U300 speedometer

Reply #10 – March 02, 2013, 08:57:21 am

The dash top cover has hinges on the forward edge, and is held down by some inside latches on the aft edge. With age the dash materials stick to things. If the dash has not been opened in some years, it will be hard to lift the aft edge. But it will with enough force, might take more than just two hands as it is so wide, left to right. Bump the overhanging edge upward with your hand till it breaks loose.

The grounds for so many things are on the front wall of the huge area under the dash cover. On mine, forward on the far outside are at least 3 lugs with lots of black wires. You will want a meter to check that you have the ground lugs correctly identified. And then remove and clean both ends of the ground wire connected to the speedo.

The nuts are going to be something between 1/4 and 7/16. Two feet of wire should be more than enough to do the job, just take some extra.

You were planning on taking a tool box, meter, and some misc wire and connectors of course? Seems the more tools and supplies I take, the less of them I need. Plus it might be time to be looking into GPS units. They have speed readouts, but will have much more in the way of routing that you are going to be enjoying soon as well.

Re: '93 U300 speedometer

Reply #11 – March 02, 2013, 09:20:11 am

As Steve Mudd stated..............I use my gps for speed and miles traveled to ack up my speedo.
It will get to you home where you can trouble shoot.
( I had to install a new one when I bought my coach 4 years ago. It also had not been driven for a long time)

Re: '93 U300 speedometer

Reply #12 – March 02, 2013, 09:31:57 am

David, if you have a GPS, most give mph. So does the silverleaf system on a PC but i dont think you have an electronic engine. Either one you may want to have long term anyway.

My dash hinges on left on the front hinges in the back

Re: '93 U300 speedometer

Reply #13 – March 02, 2013, 10:00:30 am

We do have a gps, so I think I could have it with me. Jo Ann will be in the car. Yes, I'm bringing a tool box. It weighs a ton and normally lives in the Mountaineer. We'd rather take her Lincoln since it uses less fuel, but I've had a sore back the past two weeks, so moving the tool box into the deep trunk of the Lincoln may not be a smart move.

Actually, my biggest concern is that there is only about 1/3 of a tank of fuel in the coach. Refueling will be easy (expensive, but easy), but I'm guessing that there is a bit of water in the tank. We will have Coach-net in place before we leave here for there. There are some extra filters in a bay drawer, but I don't know what is what. Odie did say she has 10 pages (!) of notes for us, so I'm hoping that some of that will be information about fuel filters.

Re: '93 U300 speedometer

Reply #14 – March 02, 2013, 10:53:13 am

Food for thought: "The owners said it has been this way for years, and they just drive by the tach". This also means the miles have been going by without recording on the odometer. Important for oil changes, etc. as well as the overall price they are asking. Failure to fix the speedo could also indicate the level of overall maintenance.

Would check the speedo sender underneath the rig. Easy for moisture/chemicals to corrode the connections.

The U300 is an electronic engine.

Pierce

Re: '93 U300 speedometer

Reply #15 – March 02, 2013, 11:13:10 am

No, the miles have been recording, so the problem lies with the speed indicating portion. I'm hoping that Odie can show me how to access the engine information on the monitor. The backup camera doesn't work, but at this point I don't know if the problem is with the camera, the cable, the monitor, or something else. Even after that's fixed I think I'll still plan on having one person outside the coach while the other one of us is doing the backing.

Re: '93 U300 speedometer

Reply #16 – March 02, 2013, 11:13:22 am

Just a thought, with the DDEC setup, would the mileage show using the VMSpc as it does with the Cummins electronic set up ? All might not be lost.
FWIW
Dave M

Re: '93 U300 speedometer

Reply #17 – March 02, 2013, 11:22:08 am

If the odo is working then the speedo is probably bad. Suggest you send it in to one of the speedo shops listed in Barry's post above. You could call them first and describe the problem. I have always used North Hollywood VDO Speedometer (Los Angeles) but expect there may be closer shops to you.

Dave has another good idea about the VMSpc. Bill Chaplin, you have one on your U300. Does it record total mileage?

Pierce

Re: '93 U300 speedometer

Reply #18 – March 02, 2013, 08:46:11 pm

yes, the DDEC has total mileage and hours, mpg from get go and lots of other stuff.
Any Allison/Detroit facility will read it for you ( some at no cost/ other $150.00 )

Re: '93 U300 speedometer

Reply #19 – March 03, 2013, 12:13:01 am

New VDO speedometer 0-85MPH on Ebay for $53.68 with free shipping.
VDO Vision Series Speedometer 85MPH - Electronic Programmable, 12/24V, w/ resettable LCD trip odometer. For use with hall effect, inductive, OEM electronic output, and generator senders.
VDO Speedometer 85MPH Gauge 437 152 Great Price | eBay

Manufacturer: VDO
Gauge Series: Vision Instruments
Type: Prog. Speedometer w/ LCD Trip
Range: 85 mph / 130 kh/m
Voltage: 12 vdc
Bezel Color: Black
Mounting Hole Size: 3 3/8"
Connection Type: ¼" Spade

Re: '93 U300 speedometer

Reply #20 – March 03, 2013, 08:18:24 am

Thanks for the links and tips. We're still hoping to get the coach later this week, and then I'll know better what needs to be done. From what we can tell at this point, the coach has been well cared for, with the exception of some small items. Oil and filters were changed just before we saw it, and it has always been kept under a shelter of some sort. The exterior was washed after each trip. Since Weatherred's owned the coach for many years, they simply didn't need the speedometer to know how fast they were going.

Re: '93 U300 speedometer

Reply #21 – March 03, 2013, 09:25:53 am

The DDEC also is the cruise control source. It is non dependent on the speedometer.
If cruise works, it is speedo. Mine indicated 31000+/- miles, DDEC said 34271.
I would like a list of electrical diagrams that you received with the coach, to update my diagrams.

bullchapin@sbcglobal.net

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