Adding a Tachometer to a 2.3L

[jarz21]

My '92 Ranger with 2.3L and 5-speed does not have a tach and I was thinking of adding one. The local junkyard has a ('90-'92) Ranger that has the 2.9L engine and complete instrument cluster with tach. I was wondering what I would need to do to use the temp/ pressure gauges and tachometer from the 2.9L truck on my 2.3L. I appreciate any help you guys can give me!

Kevin in PA

 

[Dave R]

Personally, I just swapped in the cluster and was good to go. The sending units all report the same resistance/voltage whether they are on a 2.3, 2.9, 3.0, etc.

Don't ask me why the tach from a 6 cyl works correctly with a 4 cyl but it does. Countless other 2.3 guys have had the same experience. Though mine was from the same year donor. On the old board we used to have a thread about this subject but, no more.

 

[AllanD]

That's because the Tach on EEC4 engines is NOT driven by the primary circuit of the ignition system, but rather by the tach signal from the ignition module to the PCM.

I transplanted a 4.0 into my 1987 2.9 ranger and the original 2.9
tach works perfectly with the 4.0.

AD

 

[jarz21]

I almost had the instrument cluster removed from an extended cab Ranger at my local junkyard when I realized that it was actually an '88. My dad, who was there with me, walked back up to the building and asked if it would work on a '92, and they claimed it wouldn't. As it turned out, though, they had a '92 instrument cluster with tach on the shelf in their building! So, I trudged my way back up and bought that.

The one from the '88 looks exactly like the one from '92, so I'm sure it would've worked. I ended up tearing into the replacement one so I could put my speedometer into the cluster (to have an accurate odometer reading). Everything works, but the tach occasionally seems a little jumpy. I should've greased it or something while it was off...

Kevin in PA

 

[AllanD]

Are you SURE it was a 1988 and not a 1989 with an '89 build date?

The '88 uses the same cluster as an '83-88.

The '89 cluster was used through to the end of 1994.

AD

 

[MAKG]

Hmm, my experience was different, albeit on a gen2 (1986).

I retrofitted it with a tach. The first one I got from the junkyard was off a same-year 4banger. It was blatantly wrong. Then I got one from another 2.9L and it was a whole lot better.

If you opened them up and looked, you found that the resistors behind the tach were not the same. And if you traced the wire (green/yellow) through the tach-equipped vehicle's engine harness, it went back to the coil primary (specifically, to a junction that fed the coil primary as well as the EEC-IV computer).

Note that at least at that generation, the tach and gauge cluster harnesses were not the same. The right side connector was a different shape and only had the tach and tach-ground wires for the tach version.

 

[Turbo-T]

I'm in the middle of puting an '88 cluster with tach in my '84 with no tach. The old cluster had one connecter and the newer one has two connecters. Most of the wires are marked the same, a few aren't. The signal wire for the tach comes off the negative side of the coil primary just like an old points ignition.