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My 1995 Jeep Grand Cherokee (4.0) speedometer works intermittantly. I changed the speedometer transducer at the end of the transmission but the speedo only works about 20% of the time. Is there a "computer" that controls the speedo?


did you check the gear that

did you check the gear that rides on the output shaft in transmission?

Yep. I recently replaced the

Yep. I recently replaced the gear at the end of the transmission from a Jeep dealer...... original Jeep repalcement part(Jeep dealer called it a 'tranducer'). The Speedo worked about half the time. Seemed to work 90% of the time when on long trips. Now it only works about 5% of the time.

The speedo comes on sporadically so the new transducer/gear device is working. I has 3 wires that go up to the "computer" that drives the speedometer.

did you get it keyed in the

did you get it keyed in the right pos. the transducer housing is off set to center, so if turned while in trans. housing the gear goes closer to shaft or farther away.

Yes. I "keyed" the shaft on

Yes. I "keyed" the shaft on the transducer into housing........... I notice the 'flat spot' on the shaft from the original and from the new Jeep part. I would think that if this were not engaged the speedometer would not work at all. On long trips it will work faithfully for 300 miles nonstop. The next time I stop the car and engine it may fail to work at all for an hour and then come on again for a while. Totally sporadic.

Is there a "computer" between the transducer and the speedometer?

Any luck getting your

Any luck getting your speedometer fixed? My 1995 jeep has the same issue.

what have you checked so far?

what have you checked so far?

Nothing so far. Just

Nothing so far. Just checking the internet first to see if maybe there is a cheap and easy fix that someone knows about. Any help would be appreciated. I'm putting my Jeep up for sale and want to make sure the speedometer is working first. Trying to avoid an expensive fix.
Thx.

is it a standard or

is it a standard or automatic?, only problem in cluster other than ?
is the check engin light also on?
let us know, it will narrow it down a bit.

It is a 4wd automatic trans.

It is a 4wd automatic trans. The check engine light does not stay on. Everything else in cluster works fine.The speedometer works ok maybe 10% of the time. 70% of time it doesn't work at all. 20% of time it jumps around or it reads way too fast.

ok, the reason i asked, is

ok, the reason i asked, is besause the transmission uses the same speed sensor as the transmission to make it shift, so if the transmission works correctly but the speedo doesn't, than i would think it is a problem in the gauge or wiring to it.
try this, next time you drive it put the cruze on and see if it works correctly, agin this will narrow it down.
let us know

The transmission seems ok.

The transmission seems ok. Don't know if it makes a difference when the cruise is on - will check tomorrow and let you know.
Thanks.

if it works, most likely the

if it works, most likely the gauge or cluster.
i've banged on dash when the speedo acts up and it stopped acting up, if you do that and it starts working, i know the problem is in the gauge or cluster.
let us know

The fact that it works at

The fact that it works at times suggests a bad connection somewhere in the system. A bad computer would mean that it wouldn't work at all (and likely set a code).

Check allof the wiring connections between trans and dash guage. If all is fine, guage is the problem I've seen guages do this before).

I checked the speedometer

I checked the speedometer with cruise control on and off - there was no difference either way. Pounding on the dash above the cluster also had no effect on speedometer operation. Next I will try to check wiring from cluster to transmission for any loose or broken connections..will let you know what I find.

here's what the reading

here's what the reading should be comming in to speed sensor.
if you need a wiring diagram, i can send them to a email ad. if you like.
let me know, mws919

Raise and support vehicle, then disconnect vehicle speed sensor connector.
Connect a suitable voltmeter between black wire pin of connector and ground.
Turn ignition to Run position, reading should be approximately five volts. If satisfactory test vehicle speed sensor.
If reading is not five volts, turn ignition to Off position, then check continuity between distance speed sensor connector and cluster connector terminal C7. If satisfactory replace speedometer. If not satisfactory repair open circuit. Diagnosis of the vehicle speed sensor and circuit, the Chrysler Collision Detection (CCD) data bus, and/or the Powertrain Control Module (PCM) should be performed with a DRB scan tool as described in the proper Diagnostic Procedures. For diagnosis of the speedometer, refer to Powertrain Management / Computers and Control Systems / Vehicle Speed Sensor.

Are there any other guages

Are there any other guages acting up at the time the speedo is acting up?

let me know, mws919

let me know, mws919

All other gauges are working

All other gauges are working fine. Only speedometer/odometer are not working as they should.

have you check voltage at

have you check voltage at harness side of speed sensor yet?

I don't have a voltmeter so

I don't have a voltmeter so will have to buy or borrow one. Will let you know .

ok, remember about 5 volts.

ok, remember about 5 volts.

don't forget to wiggle the

don't forget to wiggle the wires going to the instrument panel. often loose connections can cause intermittent problems.


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