SR Tach Wiring Problem - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

shaggy240sx · 06-16-2006, 08:33 PM

So apparently I am a dumbass so I am hoping someone here can help. I tried searching both here and google and have come up with nothing (again...could just be that I am a dumbass).

I have a 90 240sx with a Redtop SR20det. I know that the 89-90 tach will not work because of something with the signal. I could not seem to track down a 91+ gauge cluster so I decided to pick up an aftermarket tach. I hooked up the power and the ground and then spliced the signal cable into the yellow/red wire on the ECU that is supposed to be the Tach signal and got nothing. Then tried to splice it to the "signal" wire on the top of one of the coil packs and still got nothing. When the power is hooked up the gauge goes to 0, so I am fairly certain the ground and power are good, it just doesn't seem to be getting signal.

Obviously I am doing something wrong (or maybe the tach just isn’t compatible...but it is brand new so I wouldn't suspect that), but I can't seem to figure out what. Any help would be greatly appreciated.

vegita319 · 06-29-2006, 02:52 PM

free bump because I'm also wondering where else does the signal for the tach coem from before the ecu.

All the wiring diagrams show ecu yellow/red for the tach signal. So if anyone can figure where the signal comes from please help us out.

Edit: after looking at the FSM, the auto tranny has a revolution sensor. My 5 speed sr tranny didnt have a revolution sensor so I'm stoked

.

TougeSR20Kid · 06-30-2006, 01:43 AM

dont do it off the ecu... on the Ka there's a green wire on the plug for the coil, thats the one to use i believe. honestly what i did is test the wires, i.e. hook it up to each one and hope for a signal. on the sr its a different story i wouldn't use the coil packs i'd prob go with one of the wires on the distributer or whatever the hell you call it. a weak power and or ground couldnt be the cause... maybe you got screwed with a bad tach, please tell me that you at least bought a decent tach

shaggy240sx · 06-30-2006, 08:12 AM

I installed a DOHC Tach last night so it is a moot point for me at this point. Might have been a crappy tach for me. Wouldn't surprise me.

Flybert · 06-30-2006, 02:48 PM

You have to use an MSD tach adapter hooked up to your coilpack wires to get a reading on some aftermarket tachs. My stack cluster and my friends defi tach does not work off of the stock tach wire.

Markovich · 06-30-2006, 10:06 PM

in my 90 coupe redtop i couldnt get any tach or speedo but everything else worked it turned out that the on plug in the engine bay was moved around? like the wires didnt match up i unplug it and matched the wires up and boom it work so check all of that idk y but my swap was like that a lot with tthe wires in different places o well

peace

06-16-2006, 08:33 PM	#1
shaggy240sx Leaky Injector Join Date: Aug 2003 Location: Colorado Posts: 88 Trader Rating: (0) Feedback Score: 0 reviews	SR Tach Wiring Problem So apparently I am a dumbass so I am hoping someone here can help. I tried searching both here and google and have come up with nothing (again...could just be that I am a dumbass). I have a 90 240sx with a Redtop SR20det. I know that the 89-90 tach will not work because of something with the signal. I could not seem to track down a 91+ gauge cluster so I decided to pick up an aftermarket tach. I hooked up the power and the ground and then spliced the signal cable into the yellow/red wire on the ECU that is supposed to be the Tach signal and got nothing. Then tried to splice it to the "signal" wire on the top of one of the coil packs and still got nothing. When the power is hooked up the gauge goes to 0, so I am fairly certain the ground and power are good, it just doesn't seem to be getting signal. Obviously I am doing something wrong (or maybe the tach just isn’t compatible...but it is brand new so I wouldn't suspect that), but I can't seem to figure out what. Any help would be greatly appreciated.

06-30-2006, 08:12 AM	#4
shaggy240sx Leaky Injector Join Date: Aug 2003 Location: Colorado Posts: 88 Trader Rating: (0) Feedback Score: 0 reviews	I installed a DOHC Tach last night so it is a moot point for me at this point. Might have been a crappy tach for me. Wouldn't surprise me. __________________ Fcuk 'em, just leave 'em pissed.

06-30-2006, 10:06 PM	#6
Markovich Leaky Injector Join Date: Apr 2006 Location: lancaster,pa Posts: 96 Trader Rating: (0) Feedback Score: 0 reviews	in my 90 coupe redtop i couldnt get any tach or speedo but everything else worked it turned out that the on plug in the engine bay was moved around? like the wires didnt match up i unplug it and matched the wires up and boom it work so check all of that idk y but my swap was like that a lot with tthe wires in different places o well peace __________________ 7-mount sr20det evo3 16g in a 90 240sx coupe yes its a nisclipse bitch

06-29-2006, 02:52 PM	#2
vegita319 Zilvia Junkie Join Date: Aug 2004 Location: Long Beach, CA Age: 39 Posts: 460 Trader Rating: (1) Feedback Score: 1 reviews	free bump because I'm also wondering where else does the signal for the tach coem from before the ecu. All the wiring diagrams show ecu yellow/red for the tach signal. So if anyone can figure where the signal comes from please help us out. Edit: after looking at the FSM, the auto tranny has a revolution sensor. My 5 speed sr tranny didnt have a revolution sensor so I'm stoked .

06-30-2006, 02:48 PM	#5
Flybert Post Whore! Join Date: Mar 2003 Location: none Posts: 3,862 Trader Rating: (7) Feedback Score: 7 reviews	You have to use an MSD tach adapter hooked up to your coilpack wires to get a reading on some aftermarket tachs. My stack cluster and my friends defi tach does not work off of the stock tach wire.