Thread: tach not working

i recently just bout a 94 sentra with a SR20 swap, and the tach doesnt work. I believe the tach is a 91-92 se-r tach if that matters. Idk where to look to fix this so can someone point me in the right direction.

If it's swapped, then you'll likely have to repin the cluster and add a wire for the tach from the plug next to the ECU. That's what I had to do on my B14 when I swapped from GA16 to SR20VE.

ok after turning my car on again I noticed the needle just floats at 3000 or bonces from end to end.

It's getting a goofy signal. You most likely need to repin the cluster. Do the rest of your gauges work? All the lights work? Blinkers?

yes the lights and blinkers both work, just the speedo and tach are messed up. The temp gauge and gas gauge are straight as well.

Your speedo doesn't work because your car is a 94 and the gauge cluster is out of a 91-92. The 91-92 uses a cable speedo where the 93-94 uses an electric speedo. The tach is probably getting a goofy signal.

im not sure what year the tranny is, how could i tell if it is cable or electric?

You may need to remove your intake to see it, but if you look down on the transmission, directly below the throttle body, you will see the speedo sensor on top of the bell housing. If it has an electrical plug hanging out of it, then it's the newer speedo sensor. If it just has a hole with a threaded tube around it, then it's the cable speedo.

ok it was a PITA to find but its a cable speed sensor.

i just looked under the dash and found a connector just dangling, ill upload pics a little later

Pull your gauge cluster out, and check if it's missing a plug. You have to pull the center bezel around your radio and HVAC controls and the gauge trim with the mirror and light dimmer switch to get to the gauge cluster. Then the cluster just has 4 screws.