I recently had some issues with my transmission shifting hard and after having the check engine light come on I read the codes and saw I had a bad speed sensor. The code didn’t say which so I swapped both (one on the rear diff and the other at the back of the trans) the one to the back of the trans fixed the bad shifting and cleared the engine light but I’m still getting 0mph when coasting. The rear ABS sensor is the second one I’ve gone through in a month and each time I replace it my speedo will work for a day or two before malfunctioning again. Is it possible that a connection to the rear abs sensor is shorting/frying the new sensors I’ve installed?

 

Welcome to the forum

You should include the year of the Ranger with questions, also engine size

You have a 1997 2.3l Ranger, 2WD

The rear axle sensor is only for ABS system in 1997
It was only used for "speed' in 1998 to 2000 Rangers
Yellow ABS light will come on if the rear axle sensor fails in ANY YEAR Ranger

So no speedometer would be Transmissions VSS sensor, or wiring


1997 VSS runs off a GEAR drive in the tail shaft of transmission
Check the the gear is OK

But from your description it reads like a wire issue, since changing the rear axle sensor made speedo work, and there is NO CONNECTION between rear sensor and speedo, so you must have moved VSS wires a bit, but not sure how

But you are on the right track
Transmission VSS is connected directly to speedo and computer, also Cruise if you have that in a 1997 Ranger

1998 and up Rangers had no VSS on the transmission, didn't even have the Hole for it

 

ok got it. I did re-use the old gear when I swapped the VSS sensor. How do I tell if the gear is bad? It looked pretty clean and spun rather easily when I used my fingers to adjust it. My ABS light is illuminated as well. As far as wiring goes, I replaced the harness to the rear ABS sensor today to no avail and the connection to the trans-mounted VSS looks good as well and I assume works since replacing the sensor stopped my hard shifting and check engine light.

 

Gear would look chewed up if it was bad

You can spin the gear/VSS with a drill and if key is on speedo should show a speed if its working, makes it easier to trouble shoot vs going for a drive
Can't remember which way to spin it??
But doesn't hurt it to spin backwards, just no speed signal, same as Backing the truck up in Reverse

Computer will set a code, P0500, and turn on CEL(check engine light) if there is no speed signal from VSS at the computer
If you have an OBD2 code reader that can do live data, you can check the speed signal at computer using that device

VSS is a VR sensor, it generates its own AC Voltage, yes AC not DC
As the gear spins you get 0.5vAC and up to 7vAC at say 70MPH

You can remove the VSS and bring it to a bench or ??, use a drill to spin it and test AC Volts on the two connectors, to make sure its working as it should, higher RPMs = higher AC volts
New doesn't mean "it works" anymore, it means NEVER TESTED so grain of salt trusting "new" parts

VSS will have 2 wires, one is Grounded, you can test that with OHM meter, usually the pink wire is the ground
The Grey/black wire is the signal wire that runs to the speedometer, computer and Cruise

Grey wire is just split/spliced to the 2 or 3 devices, usually in the cab somewhere but not sure on that
You may want to just pull out the instrument cluster and test the speed signal wire on the back
Could be wire is good and speedo died, not common but does happen

One thing I forgot to ask, does Odometer work?
It uses same speed signal wire, so if Odo works then speedo is bad, if both don't work then wire or signal is bad


1997 cluster wiring below
In the middle you can see the VSS wires and what they connect to

 

Looked it up and saw that new wheels/tires can call for a new speedo gear as well. Spent $7 on a new gear after doing the formula for my wheels and I’ll see if that fixes anything. Yea my odometer works and the speedometer works while accelerating. Just when I tap the brakes while coasting it drops to 0…

 

Reads like a loose wire at back of cluster, brake pedal is moving the wire

There is no electrical connection between brake pedal switch and cluster/speedometer

 

theres an idea! I’m taking it to my shop next week since I’m kind of at a loss here.

 

Ok fixed the issue. Turns out the speedo had to do with a faulty ground on my aftermarket cruise control. Relocated the ground and it’s operating as normal