RPMs wont work

[92a6]

ok my brother just recently bought a 90 accord and the rpm gauge dont work dose any1 know how to fix this?

[cloudasc]

Check the signal wire for the rpm guage. I am pretty sure the other end of it is at the distributer.

[92a6]

whats the signal wire

[cloudasc]

When it comes to guages, there are typically only 3-4 wires for each guage. One is for power, one is for ground, one is for lighting, and the other is signal. All the guages in our cluster share a common power source/ground/lighting, so the only thing else to really check is the signal/feed wire from the distributer. Without a signal, the rpm gauge doesn't know how to move.

[92a6]

is there a diagram out there for this or something. when i went out to look there was like 3 plugin spots behind the distributor

[esskater892]

there should be two wires on the transmission also that you could check. like right under the lower coolant hose. on the newer ones its a green and yellow wire i believe.

[92a6]

ok i do see the green and yellow wires its like a plug or something what do i do now should we just pull it out and replace it with one from the junk yard? or what lol

[oyajicool]

Yellow wire is power.
Black wire is ground.
Blue wire is signal. And it is connected to Ignition coil, according to wiring diagram.

I thought it was connected to Ignition control module.

If other instruments are in working order, it is safe to assume power and ground are in working condition. So, as suggested check signal wire for continuity, making sure the signal is reaching the tach. If the wire is good, you may have a faulty tach, provided the engine is running fine.

[cloudasc]

If the signal wire connects off the coil, since he has a 90, he should have an internal coil, so it would be inside the distributer.

[92a6]

If the signal wire connects off the coil, since he has a 90, he should have an internal coil, so it would be inside the distributer.

yeah we cant work on it atm cuz hes got to go to work