Question about tachometer in gauge cluster

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Feb 26, 2019 | 12:25 PM

Blaine.MJ

Thread Starter

Newbie

Joined: Feb 2019

Posts: 28

Likes: 2

From: North Carolina

Year: 1988

Model: Comanche (MJ)

Engine: 4.0l Inline 6

Question about tachometer in gauge cluster

Trying to help out a fellow Comanche owner. He wants to swap in the gauge cluster from a 1988 Jeep Cherokee into his 1987 Cherokee 2.5l Inline 4. Can you swap in a full gauge cluster tachometer from a 1988 Cherokee 4.0l Inline 6 to a 1987 2.5l In-line 4 Comanche?
Can you / how do you adjust the tachometer to work with a 4 cyclinder?
Thanks

Feb 26, 2019 | 06:07 PM

Wabrown

Newbie

Joined: Dec 2017

Posts: 27

Likes: 6

From: SE Oklahoma

Year: 1999

Model: Cherokee (XJ)

Engine: 4.0

I did a similar swap in my '91 2.5 Comanche with the cluster from a '93 4.0 Cherokee. I know that I was able to adjust the tach from 6 to 4 cyl readings by adjusting the small blue potentiometer on the tach. The adjustment has 3 settings and as I remember it the middle position was for a 6 cyl and you went one click counter clockwise for the 4 cyl. I would do a further search on this site to conform that direction. After I swapped the oil pressure switch to a gauge sender, and the water temp from switch to sensor it worked perfectly. Two years later it still does.

Feb 26, 2019 | 06:11 PM

DFlintstone

CF Veteran

Joined: Aug 2011

Posts: 10,489

Likes: 24

From: Nor-Cal Coast

Year: 90,84

Model: Cherokee

Engine: 4.0,2.5

If he doesn't find this post, contact cruiser54 He probably knows. I vaguely remember reading that somehow it DOES work and being a little surprised. (could be the signal from the ICU to the tack always tells the truth, regardless of the # of cylinders). The tack DOES have it's own wire to the ICU , heck, or it goes through the ECM to the ICU. Check with Cruiser, my bet is they swap. (changing from idiot lights to gauges requires different senders for oil and temp)