recently bought a 96 fxdl. my know how was limited to 70's shovels. speedometer, (digital/analog), key on, needle begins to vibrate, and slowly roll counter clockwise to the 120 position. riding and gaining speed, it will slowly roll back towards zero. with key on, it rolls backwards to 120. unplugging the vss changes nothing. pulled and cleaned the vss. no change. multi meter showed 6/7 volts on the red wire. i dont want this speedometer as the digital odo is un readable. but harley has discontinued said speedo, and has no info on replacement, harness to use other speedo, etc. can an aftermarket be wired to the vss and work? ebay does have a few that are the right one but im not a trusting guy, and most have excessive mileage or inop odo. dont want to use a gps speedo, but may have to. this is the 3 3/8th? twin speedo/rpm tank mount set up.

 

It reads like you have a 1996 FXDL, a dyna frame harley.

The speedometer is having needle issues and the LCD odometer is no longer readable.
Keep in mind that needle issues are sometimes voltage related..High voltage or regulator problems...AC voltage leaks.
It would be a good idea to make sure that AC voltage is not leaking backwards.
DC over voltage voltage at battery terminals should be reviewed too.

Regarding LCD odometer bleed/leak. That was common in that era..
The LCD can be changed if a donor speedometer is located.

Regarding changing the speedometer:
Miles are stored in the speedometer for that era.
Buy one new and it starts at zero, used marks whatever is in the used unit.
The 5 inch speedometers(fatboy, road king, softtail) have a wire sub-harness available that makes a change to the plug and play 1999-2003 easy.
You report a 3 & 3/8 size speedometer.
Perhaps similar harness is available for your application online via J & P cycle.

The part number on sticker does not checkout with Ronnies..i see 67025-96 but you would need to check
Link for online parts finder in order to review part numbers. https://partsfinder.onlinemicrofiche....asp?make=hdmc

I would start at checking voltage first..DC and AC

 

Drag has one that I think will work. IIRC it's for later TCs but comes with a pigtail to wire into your own harness..

 

The drag speedometer looks like a good choice for original poster based on price point and since it allows calibration based on instructions available.
They should first confirm that charging system is functioning correctly to avoid potential damage.
https://www.denniskirk.com/drag-spec...rd/4001688.sku

 

basic electrical seems to be within norms, high 12s@ low idle with high 13/ low 14v off idle.(did have to buy a new battery when i bought it) as for the speedo.im not worried about actual miles as i am a speedometer. apparently the odo hasnt worked thru several owners as they all had it titled exempt. the universal "hard wired" speedos, generally connect not to the vss, but the signal the ecu spits out FROM the vss. iv been having a hard time with everyone not being able to tell me if you can wire directly to a 3 wire vss, and can any aftermarket speedo head read my 96 fxdl signal? fyi carb engine with only an ignition ecu, as far as i know.

 

called dennis kirk on the advertised speedo. told it will NOT work on the 95/98 bike in question. the same answer iv gotten from everyonne i talked to. ether need the oem, or a gps style.

 

Did you also check for AC voltage as indicated earlier?
I can see you reported some voltage...guessing DC
Check for AC voltage too....Not just DC voltage.

A bad regulator can knock out a speedometer.
The stator makes AC voltage and the regulator then converts to DC.
An AC voltage leak can do funny things to a speedometer.

With a real computer.
Consider review of the link provided from dennis kirk.
Look at instructions tab...Bottom right.
Click the instructions tab and open.
Review page 3 within instructions tab.
It shows how to connect.

 

Did they say why? The instructions say it will fit 96-98 Dyna. Maybe Try JnP. I've not had good luck with DK customer support..





From the looks of the instructions it's really for a 2001-2003 as it has security and engine light. Security on Dynas started in 2001. 2004 speedo started getting the speed via the serial buss from the ECM/ICM.


Add. The big thing is that on the earlier models You have to use the harness that comes with the older speedo. You cut it off then solder in the connector..

 

even on the website, got a little excited, because it didnt go straight to, "this does not fit your model'. instead, it had a ? and said this item is not specifically designed for your model. when i called and talked to one of their techs, (i was transfered to the technical dept), this guy said not, "this speedometer will not work on your model year". and, i dont know of anyone who makes one that does. now i did go to the directions of installation and set up, and physically all the wires are there to hook up as instructed, i may have been backward thinking, but still on the right track.. the vss on my model does NOT go thru an ecm, but goes directly to the speedo head, and the speedo reads the ppm and converts it to mph.the poss exists that the vss, on ecm models, sends a different ppm, signal that the ecm converts to mph. i dont know. this has all been extremely frustrating.

 

It didn't go to the ECM until 2004. The was a pulse signal from the speedo back to the ECM for the ecm to get vehicle speed.