Erratic Speedometer

[DOWG]

Last week the speedometer died. Dead. No movement. A year ago I had an erratic speedometer; wild flucuations. I pulled the speed sensor on the rear end, cleaned it and the problem went away. Now it is dead with no speed registering at all. I removed and checked the speed sensor; it was clean and looked to be in good shape. I have read on TDR that they go bad, so I bought a new sensor and installed it. It worked fine for two days and now I get wild flucuations; I speed up and it goes down, I slow down and it goes up, etc. I do have the Abbott EPRA installed for my Ricksons but I don't think that's the problem. Any ideas?

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1998 Driftwood Extended Cab,Short Box,12 Valve,4X4,Auto,Dunrite TC,3. 54,Banks Plate,AFC Spring Kit,Isspro EGT,Rickson 19. 5's,Abbott EPRA, Rancho Shocks,Heim Trackbar,Mag-Hytec transmission Pan & Pumpkin Cover,Amzoil Synthetic's,Ranchhand Bull Nose Front Bumper, Headache Rack,Tool Chest,Side Steps,Rear Bumper and 100% Stock Airconditioning.

 

[DennyDay]

They (DC) had a bunch of sensors go bad with an open circuit. Mine went out last week at 68k miles. They also pulled the rear cover and found trash on the piece that triggers the sensor. Doesn't take but a few minutes to clean and should take care of the problem

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Denny
'99 2500 4X4 White short Q cab to much added to put here

[This message has been edited by C. D. Day (edited 02-20-2001). ]

 

[Missouri Mule]

DOWG,
Take ohms test on sensor and if possible on wiring going to it or at least make sure power is getting to the sensor(5 volts). Also check connector make sure pins are not loose/bent.


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Bill Thomas
Missouri Mule - 96 Wht 4X4 ST CC,5 spd, 3. 54, 8 ft bed, 1 ft high cheater boards.
99 Freightliner bl/wht FL60 ISB-5. 9 24v,215 hp,520 tq,6 spd, 3. 59 nsr,16 ft box, 19. 5 tires,Wt/gvw 11,000/23000

 

[DOWG]

The Speedometer starting working again, sort of. It still has the flucuations or what I now call a "floating" speedometer needle. I checked the voltage to the rear wheel speed sensor as suggested above and it was OK. Sometimes the speedometer would hold steady and I was able to compare it to my engine rpm's. I usually run 1800 rpm's at 70 mph and it was showing 64 mph at 1800 rpm's. The difference was 10% which is the amount my speedomter is off due to the addition of my 19. 5" Ricksons. I then suspected the Abbott Electronic Pulse Adapter used to correct my speedometer calibration was the problem. I unhooked the Abbott EPRA and again showed the 1800 rpm's at 64 mph; the Abbott was dead.

I called Dan Richter at Rickson Truck Accessories, discussed the problem and he immediately said he would ship me a new Abbott. Good to see a vendor who stands behind the products they sell. I also called Abbott directly and they said the EPRA will have a circuit fail every once in a while.

Thanks guys for your trouble shooting input. This forum is great because no matter how small the problem, TDR member's are ready to offer experience based suggestions to help isolate and solve the problem.

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1998 Driftwood Extended Cab,Short Box,12 Valve,4X4,Auto,Dunrite TC,3. 54,Banks Plate,AFC Spring Kit,Isspro EGT,Rickson 19. 5's,Abbott EPRA, Rancho Shocks,Heim Trackbar,Mag-Hytec transmission Pan & Pumpkin Cover,Amzoil Synthetic's,Ranchhand Bull Nose Front Bumper, Headache Rack,Tool Chest,Side Steps,Rear Bumper and 100% Stock Airconditioning.

[This message has been edited by DOWG (edited 02-25-2001). ]

 

[monkfarm]

Is the abbot EPRA a stock item? Or is that a Rickson provided vendor item?? I've had a difference of 5 mph at 70 mph (indicated 70 actual 75mph) I took it in to a dodge dealer and they check it out, confirmed the speed difference and said that was an acceptable error, that I would have to live with. I'm wondering whether this would help my situation. . . ??

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'99 3500 Quadcab Laramie SLT with customized aluminum flatbed
B&D bombed with Jakebrake, firestone air bags;
5 speed,6X4, truck mirrors, trailer towing, and camper pkgs.

Ranger Cb with Messenger kicker
Amsoiled throughout. . .
2000 Peterbilt 379 with Cummins N14plus 500 hp
13 speed fuller, 70 inch Unibilt sleeper
American Class

 

[DOWG]

No, it is not a stock item. I bought the Abbott Electronic Pulse Adapter from Rickson.
Call and speak with Dan Richter at 800. 587. 7633.

Have you added larger tires? If not, I would be a little ticked off with DC about it. It seems to me that if your speedometer is off, with or without a change in tires, the Abbott EPRA may solve the problem. What I did was run down the the highway checking my odometer against the mile markers and finding the percentage difference. I then checked in the EPRA manual for the dip switch settings and adjusted the Abbott internally according to the instructions. Dan could probably give you more insight into how to help. Also, if you have 4 wheel ABS they are still working on a box for that application (I only have rear wheel ABS).

Hint: I learned the hard way that if you use the mile markers find as long a stretch of road with mile markers as possible because sometimes they are not always a mile apart... .



[This message has been edited by DOWG (edited 02-26-2001). ]

 

[DOWG]

Update on the replacement of my Abbott EPRA. (No, I am not obssessed with my truck). Installed the new EPRA and then the speedometer started "floating" again. I called and spoke with Lee Owen at Abbott Enterprises and she was very helpful in helping me troubleshoot. Lee first suggested I run the EPRA ground wire directly to the battery instead of to the chassis which can cause electrical interference. I rerouted the ground wire and the problem is gone.

I have had a problem with the ABS & Brake dash lights coming on for no reason ever since I bought the truck. Is it possible to just remove the the bulbs for the lights without creating another problem?