Tachometer help

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Does anyone know where the tach wire is in the engine bay? The speedometer works, that’s why I think it’s in the engine bay causing it not to work. 07 Liberty btw.
 

LibertyTC

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Fun & games..2007 KJ

45 min in searching the 06 Manual, where the heck is the Tac diagram I still don't know.
They did not list the TAC in the power distribution component index. EEK !!!

It would appear that the tachometer is an air core magnetic unit that receives battery current directly from the instrument cluster electronic circuit board.
 

Billwill

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You can download the 2006 KJ Service Manual here...should be close enough to the 2007 model.

Does not help too much though!
Section 8J-141 and 8J-87 tells you that the Tachometer is driven by the Crank Position Sensor which obviously works or the engine would not run.

They tell you if the Tachometer does not work then the Cluster has to be replaced and programmed properly.

You can run the Cluster Excerciser by holding IN the Odometer Trip Reset button while turning ignition ON.

All lamps get tested and the gauges should move back and forth.
Do this to see if the Tachometer does in fact move around.

Even if it does move you are still told to replace the Cluster etc.
The Cluster is basically driven by Serial busses so there is no direct wire from the Crank Sensor to the Cluster.

I would do the Cluster Excerciser test...if the Tach does not move I would try to open up the cluster and check the Tach connections on the Motherboard and re-solder them in case of a dry joint.
Then I would try remove the Tach Gauge off the Mother board and test its resistance with a Multimeter...the gauge should move a bit while testing....in the unlikely event that the gauge is faulty you would need to source a similar cluster from a Breaker Yard and rip off its gauge.

If the Gauge does move in the Excerciser Test but otherwise not show RPM then you would need to get the Dealers to try re-program the cluster or fit and program a new cluster!:(

www.colorado4wheel.com/manuals/Jeep/KJ/
 
Joined
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You can download the 2006 KJ Service Manual here...should be close enough to the 2007 model.

Does not help too much though!
Section 8J-141 and 8J-87 tells you that the Tachometer is driven by the Crank Position Sensor which obviously works or the engine would not run.

They tell you if the Tachometer does not work then the Cluster has to be replaced and programmed properly.

You can run the Cluster Excerciser by holding IN the Odometer Trip Reset button while turning ignition ON.

All lamps get tested and the gauges should move back and forth.
Do this to see if the Tachometer does in fact move around.

Even if it does move you are still told to replace the Cluster etc.
The Cluster is basically driven by Serial busses so there is no direct wire from the Crank Sensor to the Cluster.

I would do the Cluster Excerciser test...if the Tach does not move I would try to open up the cluster and check the Tach connections on the Motherboard and re-solder them in case of a dry joint.
Then I would try remove the Tach Gauge off the Mother board and test its resistance with a Multimeter...the gauge should move a bit while testing....in the unlikely event that the gauge is faulty you would need to source a similar cluster from a Breaker Yard and rip off its gauge.

If the Gauge does move in the Excerciser Test but otherwise not show RPM then you would need to get the Dealers to try re-program the cluster or fit and program a new cluster!:(

www.colorado4wheel.com/manuals/Jeep/KJ/
Ok I try it, thanks
 
Joined
Nov 2, 2019
Messages
31
Reaction score
9
You can download the 2006 KJ Service Manual here...should be close enough to the 2007 model.

Does not help too much though!
Section 8J-141 and 8J-87 tells you that the Tachometer is driven by the Crank Position Sensor which obviously works or the engine would not run.

They tell you if the Tachometer does not work then the Cluster has to be replaced and programmed properly.

You can run the Cluster Excerciser by holding IN the Odometer Trip Reset button while turning ignition ON.

All lamps get tested and the gauges should move back and forth.
Do this to see if the Tachometer does in fact move around.

Even if it does move you are still told to replace the Cluster etc.
The Cluster is basically driven by Serial busses so there is no direct wire from the Crank Sensor to the Cluster.

I would do the Cluster Excerciser test...if the Tach does not move I would try to open up the cluster and check the Tach connections on the Motherboard and re-solder them in case of a dry joint.
Then I would try remove the Tach Gauge off the Mother board and test its resistance with a Multimeter...the gauge should move a bit while testing....in the unlikely event that the gauge is faulty you would need to source a similar cluster from a Breaker Yard and rip off its gauge.

If the Gauge does move in the Excerciser Test but otherwise not show RPM then you would need to get the Dealers to try re-program the cluster or fit and program a new cluster!:(

www.colorado4wheel.com/manuals/Jeep/KJ/
The cluster exercise fixed it thank you much.. maybe it need that after I took the dash out to replace the heater core..
 

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