So I took the cluster out of my 86, and put in my 84(minus the speedo cause I wanna reflect actual miles and i dont know how to wheel it back) My question is....because my 84 is not wired for the tach, is there a way to wire the 84 for that tach? I would love to know cause I think it would look amazing to have one of the only 84's with a full working cluster.

Thanks Guys!

 

Run a pair of wires from the tach out of your 86 cluster out to your engine speed sensor. You can either use an actual Ford sensor or get a adjustable sensor for an Eaton or Rockwell transmission. You can get them at any bigtruck parts house. Same thread. Screw it till it touches then back it out a 1/4 turn.

 

Here is my think, idk where the engine speed sensor is, and my truck is a manual if that makes any difference?

 

Speed sensor is on the ip gear cover, its on the upper drivers side, looks like a 1" pipe plug, if you look at the 86 you will see it, it screws in the cover and has the two wires running from it. If your 84 is like mine you will have to switch the ip gear cover to one that has the provision for the sensor.

 

6.9 with big nut in the hole where a tach sensor would go



And 7.3 with tach sensor, standard trans or auto, no differences.

 

THANK YOU JOHN!! Once again you have helped me...I wish I could give you my 86 body for your truck, I think that would look awesome....btw....I saw your motorhome lol....there is 6 or 7 of them in Missoula, all 6.9l diesel....

 

One more question, I just went and took it off of the 86, there is a connector that goes to it...but the connector wasnt connected to anything, now what do i do?

 

I'll be doing the same. The only hold-up is the cost for the sensor! Haven't had the urge to spend 70 bucks to see that needle move haha.

I've got an '85 cab which will not be getting used again. Let me know if you need some pins with pigtails or something..

 

I'm guessing you mean under the hood? I think there's a connector for the tach that was by the thermostat housing for my original tach. My wires were so oil-soaked when I went through everything that I rewired the entire engine so mines a bit different now. I have schematics for the tach circuit. You want me to post 'em?

 

Please do, my sensor is ok, its fairly clean on the inside of the sensor, just the wiring is a bit exposed at the bolt part....but that is fixable. It is just sitting there, it has a two prong connector that the two wires run into, i would love to have the diagram so I can just do it myself....

 

1986 Instrument cluster diagram:
http://www.airplanesathome.com/FTEpi...nstCluster.gif

1988 Instrument cluster diagram:
http://www.airplanesathome.com/FTEpi...stCluster2.gif

1988 Instrument cluster connector pinouts:
http://www.airplanesathome.com/FTEpi...nstCluster.gif

The 86 diagram doesn't include any connector views and the only other information I saw for it was connector location (but we already know where that one is lol) So I included the 88 diagrams as I seem to recall they used the same connectors I think but moved things around perhaps? At any rate it should be reasonably easy to trace the circuits that go over to the tachometer to verify. Hope it helps - relatively simple to wire in

 

It seems all the IDI's have the same issue with the tach wire casing shredding at the housing cover. Not sure why, but everyone I have looked at are the same way.

 

I'm surprised mine is still in great shape, no wires showing. It is abit oily, but always worked, and never been replaced!

Once in a while in winter, driving down the road, it would jump all over the place for abit, that's pretty much it.


I've always wanted to put tach on the motorhome, you know, a lil redline for a good time

But those van clusters never came with tachs from the factory, and I hate those ugly aftermarket ones you put on the steering column or somewhere else.

 

Yeah, I always thought they were a bit tacky as well (Ha!)

bad pun...

 

They are tacky looking, my thing is, I have run into a BIG snag.....the 84 doesnt have that port for the sensor to go into on the ENGINE!! WTF?!?! How do I go about swapping the covers, or would I have to pull the IP and everything in order to do that?