Tach install issues

[B2_driver]

I have swapped in tach clusters into several rangers before with no issues but my recent truck has me confused. I have a 1996 non tach 3.0L. I installed a cluster from a 1996 explorer with tach 4.0L. Not sure if it doesnt read correct because it isn't for a 3.0 or if I have another problem. it reads about 1200 at idle and it is actually at 800. by the time it reaches 6K on the tach it is only at 4K by the OBD data feed. any help is greatly appreciated.

 

[SenorNoob]

Strangely enough it sounds like that tach is configured for a 4 cyl. I wonder if the second ground wire wasn't connected because it originally had no tach?

At least I think the newer ones work that way. I'd look into what it takes to change from the 4cyl to 6cyl or vice-versa.

 

[Rangerslpr]

tach

I am having the same problem. I have a 96 ranger 3.0 5speed nontach and replaced the dash with a tech version from an 98 ranger 3.0 5speed and it is about 800 rpm off. Same engine trans combo. Where would the second ground be?