aftermarket tach install

[spec-v5150]

I have searched

Here is the run down. I bought an aftermarket tach off ebay. It has 4 wires coming from it

1)acessory wire (so your tach only comes on in the acc position)

2)12V power (hooked to battery)

3)ground...grounded with ym HU

4)tach signal

Now I have power. I can set the point where the shift light comes on. I have the backlight. But no signal. I spliced the number 4 wire to the number 7 ECU wire. It is yellow/red and according to http://www.rb20det.com that is the tachometer speed signal. Anyone have any insight as to what I am doing wrong/didnt do???

Another thought.....

Now if I recall correctly the DOHC tach reads half the value or something like that right?? It gives a signal, just not a correct one. I have a DOHC cluster and my tach didnt budge, so could my problem lie somewhere in the swap wiring???

Another thought.....I traced teh yellow/red wire to the engine bay and I "believe" I may hae found the problem. The yellow/red wire is on a plug all by itself. It is cylinderish in shape (can't thik of a better word, but ti is the ONLY one of its kind in the bay. If someone with a swap ca look at that plug and tell me if your has some sortr of cap on it or if it is plugged into something, that would be great......

[JonPowell]

Your tach signal should come from the CAS. You computer should translate it into a tach-usable signal. The tach you bought may not be compatable with the signal from the computer. Did you try the RB tach and see if that works first?

[spec-v5150]

hey can you hiy me up on AIM or yahoo IM if you have it. my id is spec_v5150

[spec-v5150]

Your tach signal should come from the CAS. You computer should translate it into a tach-usable signal. The tach you bought may not be compatable with the signal from the computer. Did you try the RB tach and see if that works first?

Thats the thing...I didnt get a cluster. I thought the KA cluster would give you a signal just an off one. I get nothing. So that is why I think I ammissing a plug. That **** doesnt look right to me. I took the cap off of the plug in question and wouldnt ya know, there was a prong (male end) so where is the female end if there is one. So I need a pic of this thing....If there isnt a female end, I amy have to talk to the guy. IS there different types of tachs. One for distirbutors and one for coils...? I'll quote the directions exactly...

GREEN --On standard ignitions GREEN wire attaches to teh coil negative OR electronic ignitions, such as wire to tacho terminal.

So wouldnt this say it covers both of them???

[JonPowell]

It should cover both, but are you using the correct wire from the computer? I am not super familiar with the RB20 ECU, but If you have a pinout, it could help. I am downloading the yahoo im now. Hang tight

[spec-v5150]

I went to http://www.rb20det.com and it is wire number 7. yellow/red. I spliced it right by the ECU...nothing. patched that up...spliced it by the gauge cluster....nothing.......then that is when I followed it through the engine bay and found that suspicious plug

[JonPowell]

You have the wrong wire then, the wire should come DIRECTLY from the ECU and nowhere else. You must have grabbed the wrong wire. Do you have a camera you can take some pictures with?

[spec-v5150]

yup exactly what I thought...so i followed it. After I did that I thought, why would the wire be on the interior harness...duh....LOL. The wire I am speaking of went from the ECU to the engine bay to a plug with a male end. I cnat figure out how to delete old pics off my digicam...maybe I shouldnt jack **** from work...LOL

[wga240]

When I wired up the RB tach into my KA cluster, I used #7 yellow/red wire listed from the info on rb20det.com and it works fine. But, here's the thing. On my car the tach wire comes from the ECU and goes to a white plug that plugged into the interior harness on the R32. The temp gauge wire was also on this plug, so I assume this is the plug that connected to the R32 gauge cluster harness. Anyway you should have a similar plug coming off your ECU with a yellow/red wire on it.

[spec-v5150]

I have a plug with the/a yellow/red wire on it. No othe wires at all. Hey what is your email..I'll email it to you.... It is a roundish plug with the wire. but the plug looks only half complete.......

[spec-v5150]

Here is a pic. This is the plug in question. Can anyone with a swap or know how tell me if this plug has two ends. Mine was capped off. But my gut tells me there is another end to it. I want to be able to call Venus on Monday to request a new harness/plug/whatever

[spec-v5150]

When I wired up the RB tach into my KA cluster, I used #7 yellow/red wire listed from the info on rb20det.com and it works fine. But, here's the thing. On my car the tach wire comes from the ECU and goes to a white plug that plugged into the interior harness on the R32. The temp gauge wire was also on this plug, so I assume this is the plug that connected to the R32 gauge cluster harness. Anyway you should have a similar plug coming off your ECU with a yellow/red wire on it.

Okay....by my ECU, I have 3 white un-unsed plugs. 2 of them have yellow/red wires. Should these be plugged into something for me to get a signal........

[spec-v5150]

:ylsuper

After spilling my guts to Nismo241 we figured it out and I feel dumb. Basically I spliced the wire from the ECU to the gauge cluster plug and what do ya know the DOHC cluster works...just reads off. SO, I spliced the tach wire into the already spliced wires and BOOM......we have idle and we have correct reading. I figured it would be something dumb. I was tracing wires everywhere. and it was right there

[vwluv10338]

Glad you got it fixed man. Always something small, just like your boost gauge =^)

Eric