96 s14 tach issue

[240zach]

so recently i had an alternator issue and it made my gauge cluster tweak out and then my tach just dropped and stopped working..so after i fixed the alternator issue and everything my tach still doesn't work. i changed the gauge cluster to another one and my tach still does not work. i checked my fuses and they're all good. so idk what could be causing this.

i thought about unplugging the dash plug and then just replugging it back in to see if that would fix it just because 240s are fucking weird. lol but id like some input on what could be causing this. thanks

[Brentbohn]

I've had issues similar to this but not with the tach, what the cause of them has always been the same two areas of concern
1. Bad grounds
2. fender harness rubbed through and not repaired properly.

I would check both of those. keep in mind how old our cars are and that the wiring is getting brittle with age.

good luck.

shop teacher used to say weird shit = bad ground.

[240zach]

Haha. Yeah, ground to what though? I can check my chassis harness. I don't think any of its rubbed through though. And it originally stopped working when my alt was tweaking out my car. Idk man /:

[Andres_G]

While the above two areas of concern are valid, your tachometer might of just failed. It's electronic, and electrical components wear out or just stop working. My tach quit working on me also. What did I do? I bought somebody else's partially broken cluster for cheap, and swapped tach gauges. Now I know when to shift. Lol

For trouble shooting, go to your FSM and figure out which one is your tach signal wire that feeds into your cluster. Then, take a multimeter to it and measure for voltage while you rev the engine. Rpm's go up, voltage goes up etc.

[Agamemnon]

Originally Posted by 240zach

so recently i had an alternator issue and it made my gauge cluster tweak out and then my tach just dropped and stopped working..so after i fixed the alternator issue and everything my tach still doesn't work. i changed the gauge cluster to another one and my tach still does not work. i checked my fuses and they're all good. so idk what could be causing this.

i thought about unplugging the dash plug and then just replugging it back in to see if that would fix it just because 240s are fucking weird. lol but id like some input on what could be causing this. thanks

The tach is controlled by a signal from the ECU(pin 3) to the meter(pin 12). Check your connections at the back of the meter and ECU.

[240zach]

Originally Posted by Andres_G

I bought somebody else's partially broken cluster for cheap, and swapped tach gauges.

I swapped gauge clusters....and ill check the ecu forsure

[240zach]

ecu and harness were fine...maybe i just got another dud cluster?

[blueshark123]

ill sell u a known working one for 35 shipped

[240zach]

id rather use one of my friends working ones to see if thats the actual problem then go from there. lol

[240zach]

well i checked my cluster, its fine. i checked all the wiring and all grounds and they're good.
i have signal from the tach output wire on the ecu
and i have signal in the clips on the gauge cluster harness...
so why the hell is it not working?
could it be ecu or cas?

[silver350z05rb]

So you know for a fact the cluster you bought works? Try it on another s14

[240zach]

i did. lol i took the cluster from my friends s14 before he got a white face one and i saw that everything worked. lol

[fliprayzin240sx]

Try this out...

http://zilvia.net/f/tech-talk/355077...ch-glitch.html

[240zach]

lookin at it..i feel like that should be a last resort cause im lazy and dont know anyone with a soldering gun. if i was to change out the cas or the ecu would that make any difference? even though im getting an output signal? i just feel its wierd that the tach worked when i was pulling it from my friends 14 and it doesnt work in mine. and in my original gauge cluster it went out when my alt was going out. but everything is fine now and the tach isnt back? lol wtf

[fliprayzin240sx]

You can get a cheapie soldering iron for like $10. All you have to do is melt the solder to reset them. It takes no more than 5 mins to get the gauge cluster out and another 2 mins to get the tach out.

[240zach]

but could that be it if its done it on three different gauge clusters?

[fliprayzin240sx]

NM...I misread what you said. I thought you swapped in your buddy's cluster and it started working. When you said you're getting an output out of the ECU, are you checking it at the plug behind the cluster? If not, I'd check there to make sure there's no break between the ECU and the cluster plug.

[240zach]

yes all the plugs behind the cluster have signal as well..i have no clue why it isn't working still

[fliprayzin240sx]

You checked all the grounds on the cluster? The screws that hold them on actually act as connections. For some reason on my current S14, a couple of them were off the car so my speedo werent working. No clue what the fuck the PO was trying to do...

[240zach]

everything that goes to the cluster is there grounds and everything it hasn't been touched...the only thing that is changed is that i don't have a screw at the top holding it in..i only have the two lower screws on each side

[240zach]

and btw fliprayzin i looked at that post with soldering the piece of the tach in the above thread you posted and it failed a month later and doesn't work for zenkis. lol

[240zach]

bumpage???

[240zach]

Originally Posted by Lisa1

I like this.

that was the most pointless post ive ever seen...but thank you for the free bump

[240zach]

stupid spam posting man :l

[240zach]

^?

does anyone have anymore helpful info?
fliprayzin where are you? lol

[240zach]

no ones got anything?

[Laz37174]

I have the same problem with my 96 240. I have good ground and b+ at the ignition part of the tach. Does anyone know what the TAM is on the back of the tach and what the voltage is suppose to be?