Tach issue?

[nydoking]

alright zilvia so i have a question. i have a sohc 240sx right now but ive been using a dohc cluster for a while. ive recently swapped clusters for WHAT I THINK is a sohc cluster, but to be honest i'm not really sure.
so with the dohc cluster both the speedo and tach didnt work.
with this supposed sohc cluster, the speedo works but the tach doesn't
IN ADDITION my blinkers stopped working. i replaced a fuse and the relays in the drivers side fusebox inside the car and got the blinkers working again but they stopped soon after. but anyways my main concern is as follows:
1. Is the tach on the cluster just straight up broken?
2. is there some wiring somewhere thats messed up? causing the tach not to work?
3. do i even have a sohc cluster? it looks pretty damn similar to the one i had before. 6.9k redline. the reason im thinking that it is sohc is because the speedo works.

[nydoking]

all fuses are good by the way.

[KoukiMonsta]

SOHC tach redlines at 6000
dohc tach relines at 6500

that will help you differentiate.

hows the soft copper circuit paper thing on the back of the new cluster? any obvious broken points (that would lead to no turn signal stuff...)

[dbeiler]

Download a service manual and figure out which wire sends the tach signal to the connectors on your dash gauges. Using a multimeter, watch the tach signal voltage as you rev the engine. For a 4banger, it should read about one volt per thousand rpm, if I remember correctly. (Idle should be 1 volt, 3000 rpm should be 3 volts) If you're getting the proper voltage, your dash gauge has bad connections or your tachometer is just worn out. No voltage, you need to check your chassis wiring.

[nydoking]

SOHC tach redlines at 6000
dohc tach relines at 6500

that will help you differentiate.

hows the soft copper circuit paper thing on the back of the new cluster? any obvious broken points (that would lead to no turn signal stuff...)

the copper circuit is in normal condition, and its not that the turn signals dont work, because ive gotten it to work with the new cluster by changing out a few the inside foot fuse box fuses and relays, it just didnt work for long.

[nydoking]

Download a service manual and figure out which wire sends the tach signal to the connectors on your dash gauges. Using a multimeter, watch the tach signal voltage as you rev the engine. For a 4banger, it should read about one volt per thousand rpm, if I remember correctly. (Idle should be 1 volt, 3000 rpm should be 3 volts) If you're getting the proper voltage, your dash gauge has bad connections or your tachometer is just worn out. No voltage, you need to check your chassis wiring.

thanks dude! ill get on that right now.

[nydoking]

ok so i tested the 3 screws that hold the tach from the back, its definitely getting power, and i tried grounding it and the tach still wouldnt work. the "tam" screw also had a current, so im assuming either something is wrong with the signal (mabye the ecu) or the tach is straight up broken. any thoughts?