Tachometer no longer operating

[s2cmpugh]

Good day everyone. On Sunday I went out to start the car, but the tachometer remained pegged at zero after it started. I tapped on the dash, but the needle still didn't move at all during the day while I was running around. The car runs fine otherwise and no other issues exist.

Is there a test procedure for the gauge itself to see if it's the guage or some sending unit?

How do I repair this?

Thanks,
Cris P.

[JTM]

My first guess would be the Vehicle Speed Sensor (VSS). Is your car an automatic, and is it shifting strange?

[s2cmpugh]

1991 EX, original F22a4, 5spd.

The speedometer, gas, and temp. gauge all still work fine.

[quaidum]

the same thing happened when i left my vss unplugged

either the wire has a short or the unit has failed

[s2cmpugh]

I should add that there is NO CEL.

I was under the impression that the VSS only controlled the speedometer?

[quaidum]

wait i had it backwards my tach worked but my odometer and speedo did not work

my bad

[mappyCB7]

yes speedo gets its numbers from the speed sensor. so the speed sensor could be the problem and i think if it failed it could also make the odometer fail.

[sohc4door]

if you can, pull the cluster and make sure all the wires are secure and there are no breaks, the the needle mightve slipped or just need a new cluster.

[s2cmpugh]

if you can, pull the cluster and make sure all the wires are secure and there are no breaks, the the needle mightve slipped or just need a new cluster.

That's what I was thinking. I might swing by the JY and get an rpm gauge just in case.

[deevergote]

A whole thread full of solutions to the wrong problem...


The VSS is not likely the cause. Often, tach issues are related to the ignitor, but not usually a dead tach (and running issues almost always accompany it.) sohc4door's advice is the best here... it's most likely an issue with the wiring or the cluster itself.

[s2cmpugh]

A whole thread full of solutions to the wrong problem...


The VSS is not likely the cause. Often, tach issues are related to the ignitor, but not usually a dead tach (and running issues almost always accompany it.) sohc4door's advice is the best here... it's most likely an issue with the wiring or the cluster itself.

Thanks Deev. Before I posted this, I searched and did see where a few people had to replace the igniter or the gauge in the cluster itself. I was curious if anyone knew of a test procedure so I could find out if it's the igniter or gauge. Maybe sending 12 volts directly to it or something.

The car runs fine otherwise, no missing or hesitation.

[blu35p4rr0w]

I really hope mine isn't the instrument cluster. My tach hasn't worked since I got the CB, but there are other problems leading to the distributor so I'm hoping once I put this new one on it will start showing my rpms. :/ waiting for the dealership to get my rocker arm bolt in so I can reassemble the valve train & actually get to a point where I can start the car again. I'll be peaking at this thread from time to time to see if you post any updates, s2cmpugh.