Tachometer is way off. - Ranger-Forums - The Ultimate Ford Ranger Resource


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  #1  
Old 05-25-2011
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Tachometer is way off.

So I installed some Explorer Sport gauges a long long time ago (like 6 or 7 years ago) and the tach worked perfect. Idle was right on and so was redline. But just recently the the tach is showing idle around 400 RPMs and Redline is around 4000 something.

Just recently I changed out my GEM and wiring harnesses from another ranger with power doors. But I looked at my wiring manual and it showed that the tach signal is coming straight from the PCM. So what could be the problem?
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Old 05-25-2011
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Correct. The tach pulse comes directly from the PCM.

However, the ground wires present in the cluster connector of the dash harness determine if the Ranger/Explorer tach is calibrated for a 4, 6 or 8 cylinder engine. If you swapped a V6 dash harness into your 4-cylinder truck, the tach will read 2/3 of actual RPM because of the lower number of pulses/revolution.

Quote:
Originally Posted by rwenzing

96~2003 Ranger tachometer wiring for 4, 6 or 8 cylinders:

8-cylinder: "Selector" ground configuration:
  • pin 8 of the 10-pin: (NOT connected to anything)
  • pin 16 of the 16-pin: (wired to chassis ground)

6-cylinder: "Selector" ground configuration:
  • pin 8 of the 10-pin: (wired to chassis ground)
  • pin 16 of the 16-pin: (NOT connected to anything)

4-cylinder: There is no "Selector" ground
  • pin 8 of the 10-pin: (NOT connected to anything)
  • pin 16 of the 16-pin: (NOT connected to anything)
So, assuming that you have a V6 dash harness transplanted into your 2000 2.5 truck, you'd need to disconnect the black/yellow ground from pin 8 of C216.
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Old 05-25-2011
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Brilliant answer! I just noticed that little box next to the ground wire that reads "3.0 and 4.0", and it was a V6 donor harness. I take it you had to mod yours for your V8 conversion.
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Old 05-26-2011
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Don't mean to hijack, but yes I do. What about for a 95? I can't find much info on that.
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Old 05-26-2011
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Quote:
Originally Posted by sheltonfilms View Post
I take it you had to mod yours for your V8 conversion.
Yes, recalibration is as simple as releasing the 'V6' ground pin from one of the cluster connectors and moving it to the new 'V8' position in another connector.
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Old 05-26-2011
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Quote:
Originally Posted by 95lorange View Post
Don't mean to hijack, but yes I do. What about for a 95? I can't find much info on that.
Compared to the years before and after, 1995 uses a unique cluster and a unique harness pinout and it is not clear in the 95 EVTM how the tach difference between 4 cylinder and 6 cylinder trucks is accommodated.

Based on what was done in 94 and 96, here's my best GUESS for 1995. A black/yellow wire to ground from pin #1 of the 14-pin calibrates the tach for a 6-cylinder; no ground from pin #1 of the 16-pin sets the tach up for a 4-cylinder. Remember, this is an unproven guess, nothing more.
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Old 08-24-2011
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OK so if I understand this its just plug and play to put in an instrument panel with a tach in my 2000 with 2.5 in it ranger?
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Old 08-24-2011
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Quote:
Originally Posted by mojeeper View Post
OK so if I understand this its just plug and play to put in an instrument panel with a tach in my 2000 with 2.5 in it ranger?
Yeah that is correct. I put in an Explorer Sport white faced cluster in mine and it was plug and play. Probably the easiest mod I've ever done.

My problem was with swapping out a wiring harness.
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Old 08-24-2011
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Quote:
Originally Posted by rwenzing View Post
Compared to the years before and after, 1995 uses a unique cluster and a unique harness pinout and it is not clear in the 95 EVTM how the tach difference between 4 cylinder and 6 cylinder trucks is accommodated.

Based on what was done in 94 and 96, here's my best GUESS for 1995. A black/yellow wire to ground from pin #1 of the 14-pin calibrates the tach for a 6-cylinder; no ground from pin #1 of the 16-pin sets the tach up for a 4-cylinder. Remember, this is an unproven guess, nothing more.
Wasn't 95 the year they changed the dash over and went to OBD2?
wouldn't that make it the same? as what you said above?
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Old 08-25-2011
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Quote:
Originally Posted by StxDangerRanger View Post
Quote:
Originally Posted by rwenzing View Post
Compared to the years before and after, 1995 uses a unique cluster and a unique harness pinout and it is not clear in the 95 EVTM how the tach difference between 4 cylinder and 6 cylinder trucks is accommodated.

Based on what was done in 94 and 96, here's my best GUESS for 1995. A black/yellow wire to ground from pin #1 of the 14-pin calibrates the tach for a 6-cylinder; no ground from pin #1 of the 16-pin sets the tach up for a 4-cylinder. Remember, this is an unproven guess, nothing more.
Wasn't 95 the year they changed the dash over and went to OBD2?
Yes



Quote:
Originally Posted by StxDangerRanger View Post
wouldn't that make it the same? as what you said above?
No.

The 1995 cluster appears outwardly identical to the 96~2003 style clusters but there are differences in the 95 cluster itself and its connector pinouts.
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  #11  
Old 08-25-2011
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Thanks for the reply Anthony thats what I plan on doing to mine
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  #12  
Old 09-20-2011
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Quote:
Originally Posted by sheltonfilms View Post
Yeah that is correct. I put in an Explorer Sport white faced cluster in mine and it was plug and play. Probably the easiest mod I've ever done.

My problem was with swapping out a wiring harness.
OK now that I have the 02 explorer sport cluster in my 2000 ranger every thing works but the check engine light is this common on this swap?
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Old 09-20-2011
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By saying that the light doesn't work do you mean that its on?

Have your codes read if it is.
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Old 09-20-2011
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Quote:
Originally Posted by sheltonfilms View Post
By saying that the light doesn't work do you mean that its on?

Have your codes read if it is.
no it doesn't light at all and i'm sure that the bulb is good
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Old 09-20-2011
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Did your check engine light come on before the swap?

Does it not come one when you first turn your ignition on?
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  #16  
Old 09-20-2011
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[QUOTE=sheltonfilms;1894329]Did your check engine light come on before the swap?

Does it not come one when you first turn your ignition on?[/QUOTE

yes Im sure it came on before the swap and no it dont come on when you first turn on the ignition
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  #17  
Old 09-20-2011
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Ok looks like the is a pinning difference. Let me double check all the wires for both models and see if others are switched too.

Edit: For some reason I was looking at a 95 Ranger diagrams (got confused with above posts)

Last edited by sheltonfilms; 09-20-2011 at 05:04 PM.
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  #18  
Old 09-20-2011
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Pins on 2000 2.5 and 2002 sport look identical. Check engine light pin is the same. I would say you have a bad bulb.
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  #19  
Old 09-20-2011
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Quote:
Originally Posted by sheltonfilms View Post
Pins on 2000 2.5 and 2002 sport look identical. Check engine light pin is the same. I would say you have a bad bulb.
Ill pop it out and change it and see what that does thanks for the help
Brent
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  #20  
Old 09-21-2011
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Quote:
Originally Posted by mojeeper View Post
Ill pop it out and change it and see what that does thanks for the help
Brent
well three different bulbs and sockets later I now have a check engine light
Thanks for all the help Anthony
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