Unfortunately, the install instructions start at 1985 and mine is an 84. Where does the green wire go?

 

To the Coil. What does it say for 1985, I bet its the same.

 

There should be a "Tach Test" terminal on your ignition coil (assuming you have the Duraspark ignition system), with a factory-original green wire already connected to it. You'll need to get a three way connector (looks like three eyelet connectors riveted together through the eyelet part), and splice the tach wire from the gauge into the factory green wire. You can use another method of splicing into this wire if you want, but I just used the three-way connector since it was a clean and easy solution.



Make sure you crimp all the connections well, and tape up or heatshrink-wrap your connections after crimping.

I have the very same tach you have, and this is how my uncle and I installed it. It's worked flawlessly.

If you don't have the Duraspark ignition system though, someone else'll have to explain how to hook it up. :\

 

Thats what I said, the coil. No reason to make it difficult...

Just kidding, nice write up and graphics

 

lol thanks

 

No duraspark. eec-iv or whatever it's called.

 

The green wire will splice into the ignition coil negative which is a green/yellow wire.
For reference, the coil positive is a white/Lt.Blu wire. The coil neg wire should be the top wire. Your coil is a square e-core coil which is kinda right in front of the drivers side valve cover. Of course it has the distributor coil wire running to it.

That's the easy way. However, if your instrument cluster has gauges and not just idiot lights (I think its only pre-wired if you have gauges, member "81-F-150-Explorer knows this better"), it's pre-wired behind the cluster with a green/yellow wire at the connector. You'll need to pull the cluster to get to it which really isn't that hard. This is the preferred method 'cause it keeps the engine bay looking tidy. Good luck.

 

Yes, if the truck has ammeter or oil pressure gauges the truck is already prewired for a factory tach. Just use the wires at the back of the cluster connector.

Better yet, I would go and get a factory tach cluster and swap it in plug and play.

Trucks with alt and oil idiot lights, are not prewired for a factory tach, and need to use an aftermarket one.

Just remember these important facts...

There are three instrument clusters found in these trucks.

1. Cluster with idiot lights.

2. Cluster with Gauges, ammeter and oil pressure.

3. Cluster with Gauges and Tach.

The cluster with gauges and tach is a direct swap for a cluster with gauges only. Plug and play. But they will not swap with a cluster with idiot lamps.

It doesn't matter if the cluster is for a automatic or standard transmission, as the shift selector and or blank for the standard transmission is removable and swappable as well.

and finally, 1980 is one year only. none of the clusters for a 1980 will work correctly in a 1981-1986 and or visa versa.

So to summerize...

1. A Factory tach cluster will swap with a ammeter and gauge cluster, or visa-versa, but nothing will swap with a idiot lamp cluster except another idiot lamp cluster.

2. 1980 is a one year only truck. A cluster from a 1980 will not work correctly in a 1981-1986 or visa-versa. But the clusters are swappable between 1981-1986.

Hope this helps.

 

Thanks, I have the dash with a tach, I just don't think the tach is very accurate.

 

I apologize if I am straying too far from the original subject, but my question is in line with what 81-F-150-Explorer detailed.

Will a factory tachometer [unit, not cluster] which came from a 1986 F-150 with V8 simply "plug and play" in the cluster of a 1984 F-150 4.9L with gauges and ammeter.

 

You would need the printed circut for the tach cluster as well as the tach to make that work.

But you can make it work with those two components with your original ammeter and oil pressure gauge cluster, yes.

The simplest way for you would be to unplug one, and plug in the other cluster. But if you want to keep your original speedometer, the above is certainly an option.

As for the V8 and Inline six, the same tach was used for both. How Ford accomplished this was to have TWO ground wires hooked to the tach for a V8 and only one ground wire hooked up if a six cylinder. So if the tach reads high hooked into a six cylinder, all you have to do is remove the nut off the tach on the "8" post, on the cluster, and it will work normally.

 

Thanks, 81-F-150-Explorer.

I have read much information using the search function, but still was not sure since most threads which say "plug and play" mean to swap out the whole cluster. I can understand the fact that the same tach is used as you so well described above, but what puzzles me is I know the truck has the printed circuit since it originally came with the instruments rather than "idiot" lights. I am not clear as to whether the printed circuits are the same for six and eight cylinder engines. My reasoning is that the six cylinder circuit board would be different and only have one ground, where as the eight cylinder would have two ground circuits, for the tachometer, on its circuit board.

If that is true, wouldn't it be best to simply install the tachometer in the truck using the original circuit board?

 

The Printed circut is also the same between engines, but not between tach and ammeter or oil pressure printed circuts.

1: Cluster printed circut, with Tach and gauges: Marked: E1TF-10C956-B Fits 1981-1983 F-100 and 1981-1986 F-150-F-350, with tach or ammeter and oil pressure gauges.

2: Cluster Printed circut, with ammeter and oil pressure gauges only, Marked: E1TF-10C956-C Fits 1981-1983 F-100, and 1981-1986 F-150-F-350 with ammeter and oil pressure gauges.

Both of the above are swappable with each other, no matter what engine you have, except diesel.

The Gauges, the Speedometer, the cluster plastic components are identicle between the two above. Only difference is the printed circut, and Tachometer itself.

Here is a picture...


The above is E1TF-10C956-B and below that is E1TF-10C956-C

 

Thank you, 81-F-150-Explorer. That is about as clear as one can be! The photos really helped.

Are the printed circuits usually still in good enough condition to swap, if handled with great care?

 

If you handle it with care, and do not bend it, or crease it, you can swap the printed circut fine.

While it's apart you can clean the printed circut connections with a block pencil eraser as well. Just be easy on it, and it should be fine.