On another thread I related how I had an IVR (instrument voltage regulator) failure and ended up swapping in a full deluxe gauge cluster salvaged from a neighbor's scrapped Bronco. He had commented that the tach "only worked sometimes" and after ~500 miles I've seen the needle move twice, both times when the engine compartment was very warm and heated up the back of the dash and the tach.

Something going on there but I decided to replace the tach and purchased another one on ebay. Here's the face of the one I bought.
81 82 83 84 85 86-91Ford F150 F250 Bronco Tachometer: eBay Motors (item 180567611299 end time Oct-04-10 23:20:56 PDT)



It looks exactly like the tach face I pulled from the Bronco dash and even came with the correct dash circuit (and OE IVR) but the back is totally different.


The one I got out of the Bronco was totally enclosed and the circuit board was very different .... I disassembled it and cleaned the excess glue off the circuit board before installing the tach in Clyde hoping that would fix the intermittent operation problem.



The posts are marked for the Ford wiring; Sig, Grd-8, Grd, B+



Can someone tell me what I have here? It looks good and I'll likely install it but what's the story on a Faria CB0029 tach in a Ford?

 

Looks to me like Faria was the OEM supplier of that particular gauge.

Thomas G. Faria Corporation

About the company.

 

Different design or manufacturer I'd imagne.

There isn't any diiference in the parts books, 1980-1986 with the tach only.

 

Aside from the seemingly obvious possibilities I guess I'm still just a little surprised that this one is not a Ford/Motorcraft tach. There's little Ford logos all over everything else on that dashboard AND the whole truck for that matter, why an outsourced tach?

I'd never seen one that looked like this before. I was thinking maybe earlier or later trucks, Maybe a Faria aftermarket add-on, Canadian Fords or something else ... who knows where a lot of this ebay stuff comes from. I'm still a little blown away by a site I saw a couple years ago that showed Brazilian Ford F-Series, how similar yet different they were!

When I make the swap I'll have to take a couple shots of the one I pulled from the Bronco.

 

They outsourced frames & transmissions & axles & all kinds of stuff, I suspect so they could
get 'em to the customers faster.

The other tach you're referring to, is it enclosed in a white case by itself? If so, I've seen
those....

Look at the back of the cluster assembly, does it have the white tach case portion molded
as part of it?

 

my friend hat the same problem as you what he wound up doin was hard wiring the thing in

 

Once you pull your old tach to put in the new one, you might try bench-testing the old one. Get some lengths of wire; B post to 12V, I to coil negative, and G and 8 posts to ground. By bypassing all the factory wiring, if the tach works properly, then you know that your problem is wiring related, not tach related. Also, you could use a multimeter to check for 12v, coil signal, and ground at the circuit film as well.

Several months ago I bought a tach cluster from a local junkyard, and everything (even the ammeter *gasp!*) worked. The tach, however, just sat there like a dud. Wanting to get it to work, I got on here and started asking questions, and as it turns out, I was not getting any voltage to the B post through the circuit film. If I applied 12v through a wire coming from a known good source, the tach worked. So I just ran a wire with an eyelet connector from the B post of the tach to key-on 12v, and it's worked flawlessly for months. Haven't had any problems with backfeeding, radio interference, weird electrical problems, etc.

 

As Ctubutis said, Ford outsourced a lot of parts and accessories.

Turn signal flashers, headlamps were made by Wagner for Motorcraft.

Sylvania/GE/Wagner etc... light bulbs

Wiper Blades were made by Trico for motorcraft.

Borg/Warner transmissions. / Clark transmissions.

Motorcraft O2 Sensors made by Bosch.

Ford Radio Cassette decks made by nippon-denso and placed into Philco (Later renamed Ford aeronutronics and communication) type radios etc...

 

Like I'd posted earlier, the PO also had problems with my installed tach when it was in his Bronco and I had hopefully credited that to the infamous "brown glue" problem. I completely tore the tach down, scraped and cleaned the boards with dental tools, rinsed with contact cleaner and reassembled it. When it didn't work initially I pulled it and did the hard wire thing right on the truck in addition to checking the film connections with a portable tach/dwell meter. NOGO from the hardwired tach but the film connections were ready to rock and roll.

In disgust I reinstalled the whole dash unit, we had a trip up north scheduled the next day, and went to fuel up with "No-E" gas and grab some groceries. Came out of the grocery store, fired up Clyde and unbelievably the tach was working! Drove home, the truck cooled and the tach quit. This, and the conditions the second time, led me to believe the tach works hot but not cold. Some internal contact or component has to reach a certain temp to operate. I'm not going to mess with it since repair will likely cost more than replacement ... unless it's something REALLY simple and someone tells me how to fix it so I can do it myself.

My original amp meter never moved either ..... I understand your "shock & awe", the new one actually moves!!!

Yes and Yes. IIRC I had to take the tach apart in order to see the electronics and disassemble it further to get at both sides of the circuit board to clean it, that's one of the reasons this new one surprised me.

 

It's probably a dry solder connection. Heat makes metal expand etc...

It could even be a transistor, or resistor or other such component, but these usually stop working WITH heat, so a dry solder connection is more likely.

Still, you would need testing equipment, unless the solder joint is very obvious, to diagnose and fix it. A new tach in the yards is easier.

 

The old tach is out and the new tach is in. It even works! As long as I have the dash all torn out I've decided to take the three wood grain dashes I have, mix and match as necessary and install one good one.

Here's some pictures of the Ford tach and you should be able to see why I noticed the difference.


Pretty hard to tell a difference.


Starting to see some differences between the two .....


Covers off and fastners laid out.


OK, that's different.


A lot more here than on the Faria tach ....


Ovals and Ford numbers that look much more familiar to the rest of the instruments on this dash.

Somebody understands this and I'm still very curious.

 

There were dealer aftermarket stereos made by clarion, and other manufactures, that were basicly Factory radio clones.

It's possible that the tach goes along this same idea?