Wore out my '89 Aero, just bought a '93 w/3.0l. Driven it one day now.

Trim level is XL but does have most options including power mirrors, but not dual heat/air.

I miss my tach on my digital-dash '89 already.

The '93's instruments are analog except the odometer. Was there an optional digital cluster, or an optional tach of any sort, available in 1993?

============================

Old '89 has a 4.10 Trac-Lok rear end (door sticker code A2); new '93 has a 24 (3.73 open). I bought another 4.10 axle Monday (code B2), but of course it had to have the older loop-bolt style of u-joint joke.

I think I need a later companion flange to mate it to my '93's driveshaft. Anybody have a source for the later diff's companion flange by itself? I can source a new seal locally.

Thanks for your help.

 

I install an aftermarket tach on all my vehicles if they did not come with one. It can help extend tranny life because you can observe torque converter lockup, and it is niceto know it is working. There should be a tach terminal near the master cylinder coming out of the harness. Otherwise you tap into the neagtive side of the ignition coil. I would try to find a tach terminal because it is so much cleaner to do it that way. The bet location for mountin is on the driver side post immediatly above the dash. I'll send a picture in the near future.

 

Aero with auto needs no tach... I have '89 aero with 5st tranny, but no tach and belive me, I can feel the engine so good, that I can shift without clutch depressing.

Yes, to check my engine, I connect digital tacho, but rarely.

 

The tach is nice for the automatics, because you can use it to observe TC lockup as noted above. Yes you can use lights, which is a great idea. I use it for other purposes too, like when I am pulling Seafoam through the intake. I just tell a helper to hold it at 2000 rpm. I like having one, it is just useful. Maybe I'm just a guage freak, but I especially like having one when towing. When the TC locks up, the RPMS drop by about 300, but it is often difficult to tell if you are in 4 gear with TC unlock or in third gear. You can hear the TC unlock, but the tach is more useful to me. I can also see where the engines strong point are. Mine produces the best overall power around 3,000 rpm. To each his own. I am pretty sure digital dashes are offered on newer models, but I am not sure what is different as far as hookups. They are not common, so locating one can be tricky.

 

You're right, finding the input is very confusing. I'm looking at the EVTM for my 91 and it shows the Tach Input for the 4.0 digital dash as coming from pin 4 of the EEC module. For the 3.0 it does not show that. However, I know that the 3.0 also came with the digital dash (My 90 EB extended had one). That output is labeled as "Ignition Monitor" on the pin-out for the 4.0 EEC. On the 3.0 pin 4 is also labeled as "Ignition Monitor". It is possible that this is the signal that can be used for tach input. Just my 2 pennies worth.......

Klaus Cook
Houston, Texas

 

As far as I can tell, the tach signal can be tapped directly from the connector to the Ignition Module on the Passenger Side Fender.

 

As far as I know, there is a connector for the Tachomter. It should be a single wire somewhere near the spout connector. I think it is a yellow andtan or yellow and purple wire.

 

I have a 93 EB ext with a 4.0 L and a digital dash with tach so I know it was avail. It has every option except a locking rear axle.

 

Hi hrymlrgld:

Welcome to our FTE forum

 

from Ford Serv cd
Tachometer Connection

The ignition coil connector allows a tachometer connection using an alligator clip, without removing the coil connector. This is accomplished by inserting the alligator clip into the back of the connector, onto the dark green/yellow dotted wire.

CAUTION:
Do not allow this clip to accidently ground to a metal surface. It may permanently damage the coil.

picture avail in serv cd

 

What a reason? it is so easy to make a permanent connection on TFI connector!

 

Thank you for answering my Q.

As noted by others, when towing in my '89, I could hear the TC lockup but used the tach to verify. I also had a "utility" heavy-duty TC installed, so my RPM drop was more dramatic -- three bars on the digital tach (where each bar is supposed to represent 250 RPM).

My '93 seems to be much quieter The change in RPM when the TC unlocks/locks is much more subtle (or my hearing had deteriorated in the last two weeks). I feel that I "need" a tach -- but even if I don't, I want one.

Anybody seen an analog dash with a tach from the factory?

 

Here is a picture of my setup. I do not know if the 3.0L has this same tachometer terminal, but it should for diagnostic purposes.





I drilled through the firewall just above the gas pedal. That was the most easily accessible area. I sealed the grommet with RTV to prevent noise and moisture from entering the small hole. If someone here knows a better way to route this through, let us all know.

 

According to the EVTM, that tach connector you used is 4.0l only in 1993/4. There is a similar connector but it's the STI (which will do no good). I'm thinking about putting my 'scope on the SPOUT wires that are in the same area (shown in the pic above as just above the tach connector you used). If I get a good reference signal there, that might work.

Unfortunately, I don't keep my 'scope here and I have only my "work" Fluke 23 here; my "good" Fluke 79 is at home. I'll have to do my checking some other time.

 

Isn't the SPOUT connector just for enabling/disabling the active control of ignition timing? I don't think you will get a tach signal there.