Explorer Cluster in '94, tach doesn't read right

[The_Ghost]

I swapped in an explorer cluster from either a 93 or 94 Explorer (had the blue font same as the ranger, not the orange font), and the tach does work, just it's several thousand RPM off. IIRC the rev-limiter for these cars is 6k, and I hit the rev limiter just below the 4k mark. I think I pulled the cluster out of an exploder with the 4.0L, since it had upmarket options like leather (beige) and chrome-plated 15" Aluminum alloy wheels.

Anyways, is there anything I can do to make this read right?

For anyone else doing the swap, either disconnect the speedo cable from the trans or have a friend with skinny hands and arms. There is very, very little slack in the wiring harness and the speedo cable.

Getting the speedo cable off is easy, squeeze the long flat part of the white plastic ring on the back side of the cluster, then pull on the cable itself; it will slide right out.

On the upside, all the other gauges seem to work.

On the downside, it appears I need a new coolant temp sensor (the one that sends to the gauge).

Anyone got any ideas on how to fix the tach?

Did I miss some step?

 

[4b316]

V6 gauges won't work on a 4 cyl.and read right.

 

[fastpakr]

V6 gauges won't work on a 4 cyl.and read right.

Not true with EDIS. The tach signal comes off the ignition module and is not related to the cylinder count. I'm running a V6 Explorer cluster on my '94 and it works great with no adaptation whatsoever.

 

[The_Ghost]

I also have the EDIS system.

It reads idle (probably really 700-900rpm) as about 500 and redline at 4000.

So I'm at 2/3 I think, what did I do wrong?

 

[fastpakr]

I'm really not sure what to tell you. I pulled the cluster directly from my '94 Explorer and swapped it back and forth with the one from my '94 Ranger. I've run it to 5000rpm on that tach and everything sounded normal, never hit a limiter. Maybe drop AllanD a PM to see if he has a suggestion?

 

[scotts90ranger]

mine's in the earlier wiring type, but the colors of the circuit boards were different between tach an no tach so maybe you got the wrong type, if it's from a '91 or early '92 explorer then it won't work on your truck.

 

[4b316]

Well,I learned something today.This site is great.

 

[The_Ghost]

Well, to be frank I can't recall exactly what year it is but I can tell you I really don't want to do that dash again-- hooking it up was a PITA because there is no slack in the harness.

 

[Bryan22]

If it's the same color it should work. Thanks to fast I also put one from an explorer in my 94 2.3. Your problem might not be with the guage at all but with a failing ICM. IIRC when fast had his ICM on its way out his tack was at about 1/2. I also had a problem with my ICM on very hot days and the tach would read half. might be something to look into. either that or you got a bad cluster. Also taking apart the dash is alot easier the second and third time around

 

[fastpakr]

That's a very good point. Is the CEL on/working?