Cluster Question: SOHC to DOCH Swap

[WhteldyZ]

Ok first some back ground. I purchased and '89 with a DOHC swap. Has a working HUD, but that tach does not work. I did lots of research. Please don't flame me, but I cannot find consensus on what is the correct path for my problem. From my research, I believe I have 2 options:

Option 1: Stay with the HUD cluster, wire the TAM wire from the cluster harness (yellow w/ red stripe), to inside the engine bay to the positive wire of the ignition coil. (http://forums.nicoclub.com/converting-your-sohc-tach-to-read-dohc-signal-t272023.html)

Option 2: Purchase a DOHC analog cluster and sub-harness, plug and play.

I'm going with option 2 because my HUD cluster is in rough shape and I'm going to be installing a dash cap which does not work with the HUD - I'm not gonna cut the dash cap. I'm fine with this.

I'm mid project for a refresh on this car, and I'm not able to start it at the moment. Waiting on some parts.

My question: Are my options described above correct?

I recently read more material that states the DOHC speedo will need to be direct-wired from the speed sensor to the DOHC cluster. My cluster is from a 93 USDM S13, which was DOHC. Does anyone have any first hand experience with this? Can anyone verify what the correct information is?

[kyral]

Ok first some back ground. I purchased and '89 with a DOHC swap. Has a working HUD, but that tach does not work. I did lots of research. Please don't flame me, but I cannot find consensus on what is the correct path for my problem. From my research, I believe I have 2 options:

Option 1: Stay with the HUD cluster, wire the TAM wire from the cluster harness (yellow w/ red stripe), to inside the engine bay to the positive wire of the ignition coil. (http://forums.nicoclub.com/converting-your-sohc-tach-to-read-dohc-signal-t272023.html)

Option 2: Purchase a DOHC analog cluster and sub-harness, plug and play.

I'm going with option 2 because my HUD cluster is in rough shape and I'm going to be installing a dash cap which does not work with the HUD - I'm not gonna cut the dash cap. I'm fine with this.

I'm mid project for a refresh on this car, and I'm not able to start it at the moment. Waiting on some parts.

My question: Are my options described above correct?

I recently read more material that states the DOHC speedo will need to be direct-wired from the speed sensor to the DOHC cluster. My cluster is from a 93 USDM S13, which was DOHC. Does anyone have any first hand experience with this? Can anyone verify what the correct information is?

Your options are correct. keep us posted on what route you go and what you find out, im interested for my own personal project

I know there is different clusters, idk how many there are but I know I have a cluster that goes to 110 and one goes to 115 maybe somebody could shed some light on the clusters and how to identify them

[sidewaysil80]

I’m in same boat although I’m going to an SR. Can the TAM wire be run to an equivalent component on the SR?

My only other option is to remove dohc tac and retrofit to sohc cluster I don’t want to waste money on new cluster as this one works fine

[WhteldyZ]

Your options are correct. keep us posted on what route you go and what you find out, im interested for my own personal project

I know there is different clusters, idk how many there are but I know I have a cluster that goes to 110 and one goes to 115 maybe somebody could shed some light on the clusters and how to identify them

So after some in depth wiring diagram reading, the DOHC Cluster being plug and play depends on whether the PO did this correctly or not:
https://www.youtube.com/watch?v=TgzNaFBj1h8 (there are 3 parts to this video).

If not, I'm going to have to wire the directly from the cluster to the ECU outputs. For the DOHC cluster with and DOHC ECU, refer to FSM page EL-39
and the ECCS foldout (see screenshots).

http://zilvia.net/f/attachment.php?attachmentid=102135&stc=1&d=1513606413

http://zilvia.net/f/attachment.php?attachmentid=102155&stc=1&d=1513628667

http://zilvia.net/f/attachment.php?attachmentid=102155&stc=1&d=1513628667

http://zilvia.net/f/attachment.php?attachmentid=102133&stc=1&d=1513606102

http://zilvia.net/f/attachment.php?attachmentid=102153&stc=1&d=1513628650

You can also just connect in at connection F1=M53, but is very close to the ECU anyway.

[WhteldyZ]

I’m in same boat although I’m going to an SR. Can the TAM wire be run to an equivalent component on the SR?

My only other option is to remove dohc tac and retrofit to sohc cluster I don’t want to waste money on new cluster as this one works fine

This doesn't make sense. It should be similar to my last post for the SR regardless of cluster. Find the SR ECU pinout (I'm sure there's more info for the SR than the KA). Connect the tach and speedo wires as I've shown to your DOHC cluster and you should be fine.

[sidewaysil80]

This doesn't make sense. It should be similar to my last post for the SR regardless of cluster. Find the SR ECU pinout (I'm sure there's more info for the SR than the KA). Connect the tach and speedo wires as I've shown to your DOHC cluster and you should be fine.

I am trying to retain my SOHC hud cluster and was wondering if the TAM wire/ignition coil option to convert SOHC to read DOHC signal was applicable.

[WhteldyZ]

I am trying to retain my SOHC hud cluster and was wondering if the TAM wire/ignition coil option to convert SOHC to read DOHC signal was applicable.

Yes it is. My SOHC HUD worked, but the cluster was rough. Clock was half out, odo was shot, etc. Plus I'm going with a dash cap, so the HUD became not worth that hassle for me.

But if all else on your SOHC cluster/HUD work and you would like to retain it, that option would work well for you. I've never executed it, but I did see a youtube vid for a guy with an S12 that did this and he was amazed at how simple it was. To be clear, I'm talking about the Option 1 method I linked in my first post.


FWIW, I started up my project and the DOHC cluster tach works. I picked on up with a sub harness too so it was plug and play. I have not driven it so I cannot verify speedo works yet. But the gas guage, and tach do. Currently trouble shooting an issue with the coolant temp gauge. May or may not be related to the cluster swap. I report back when solved.

[sidewaysil80]

Awesome! Thanks for getting back to me.