factory tach not working

[steve-michigan]

I have a gauge cluster that I removed from my '92 LX. Everything worked when I removed it from my car, but now the tach is not working. I rewired my '89 GT for this cluster but haven't been able to get the tach to work. I then tried hooking the tach up directly to the appropriate feeds on the '92 to verify that it was still working. I attempted this in the following way:

Connected positive battery post to contact 4 on vertical connector receptacle on back of cluster (4th contact from top on driver's side).

Connected ground wire to contact 9 on horizontal connector receptacle (2nd from passenger side on top).

Connected signal wire from driver's side coil wire (tan/yellow) to contact 11 on vertical receptacle (center on inboard/passenger side).

When I did this I didn't get any response on the tach. Am I testing it incorrectly? I also tried the other coil wire to see if that would work, but it didn't. Nothing has happened to the tach that I know of that should have caused it to stop working. Any help would be appreciated.

 

[85GTlover]

As Far as I knew you want to find the dark green wire under on the cluster and tie into that, all your description does is confuser me. Like I said find the dark green wire and attach the wire from the coil and ignition into that one. That is as simple as I can say it.

 

[steve-michigan]

You're right. This is a bit confusing. I switched clusters between my '89 GT and my '92 LX (I won't get into all the reasons why here). The circuitry is different between these two clusters because the '92 has an air bag. Therefore, I had to rescramble the wiring on each car to redirect the wires to the appropriate contacts on the cluster. Unfortunately after doing that the tach that was working in the '92 is no longer working in the '89.

In order to troubleshoot this I was trying to do a simpler "bench test" of the cluster using only the feeds necessary to get that to work in the '92 car that it came from. The dash on the '92 has been rewired for the '89 cluster (installed) so the wires there are different colors and are not real accessable.

I actually tried this same test on the '89 which has a Dark Green/Yellow tach signal wire, but that didn't work either. Sorry about the confusion, but what I'm attempting to do is take an uninstalled cluster, set it next to my engine, connect a few wires, and verify that the tach works. My thought was that this would remove any questions of dash rewiring accuracy or aftermarket coil in the '89.

Thank you.

 

[steve-michigan]

Is there anyone out there that can tell me how to bench test a 92 LX cluster to verify that the tach works?

 

[shttygtstang]

buy an aftermarket

 

[cjman15]

those ford racing 5" tachs with tha shift light look pretty cool

 

[steve-michigan]

Thanks for your thoughts. I may need to resort to that, but I was hoping to get the factory gauges all working without spending much money on them. This probably sounds kind of stupid but I actually have a 5" autometer tach that I was going to eliminate in favor of what I would consider a cleaner, factory look. How inaccurate is the factory tach (when it's actually working) and is there a simple way to test an uninstalled cluster?

 

[87TTopGT]

My stock tach is posessed, works a little, mostly doesn't work. I installed an Autometer 5" with shift light and when the stocker kicks on have seen 200-300 RPM difference between the two. Everybody I've read who installed aftermarket gauges says the stock ones are pure crap.