Tachometer mod: V6 to V8 swap

[gfennie77]

Anyone remember off-hand what exactly needs to be done to a stock 1992 Explorer v6 tachometer in order to 'recalibrate' for use with a v8?

I seem to recall that there's a resistor or jumper on the back of the instrument cluster that needs to be installed, removed, or moved to a new location - but now I need the details and I can't find the original post (argh!).



Thanks!
-Graham

 

[410Fortune]

some of the gen I explorer tachs actually have a post on the back for a V8, I suggest removing the instrument cluster.
The info on how to mod your tach and also the tach adjuster for the v8 engines used to be found on Therangerstation.com and possibly rangerpowersports.com

I have the info printed out at work, but I am working from home today so I cant get to it right now.

My 88 tach has a jumper on the back, from post to post, justs a small piece of wire, it has my tach closer to the V8 reading, but it is still not 100% accurate. My plan is to replace the guts of my stock 88 tach with the guts from a 96 v8 explorer tach, this willtake some work because the mouting is different for the tach module. My other option is to run an aftermarket tach and speedometer eventually.

 

[gfennie77]

Guess I'll pull the cluster tonight and see what I have to work with... Was there only one set of jumpers on your tach?

 

[410Fortune]

there are no jumpers on the tachomoter, there are two posts for the input from the PCM
jumpering the two posts is what gives you a semi close reading for the V8, UNLESS your tach says V8 on it.
I had to experiment with mine a bit to get the closest reading I could.

 

[WickedWindsor]

Or you can get one from an early '87 - '93 F150. Remove the unit from the faceplate, bolt it to the Ex original faceplate and Bob's your uncle.

 

[410Fortune]

I wish I could do that to my BII! it wont bolt in

 

[MoabB2]

there are no jumpers on the tachomoter, there are two posts for the input from the PCM
jumpering the two posts is what gives you a semi close reading for the V8, UNLESS your tach says V8 on it.
I had to experiment with mine a bit to get the closest reading I could.

Jumpering???

So what do I need to do Jamie? Run a wire between the two posts?

 

[410Fortune]

yep small wire between the two posts will get your tach closer but still not accurate

I am ditching the stock dashpot next and running real 5" gages that will work with my cable style speedo and the 97.5 computer (tach)

check out:
www.v8-ranger.com/tach/tach.php if hes still around

 

[RatStang]

Here is the Tach back.
Which pins?

 

[410Fortune]

I cant remember! Let me search around and see if I can find it.
I didnt take a pic of mine I dont think

http://www.rangerpowersports.com/forum/showthread.php?t=155003&highlight=v8+tach

 

[MoabB2]

Rat, apparently there is an earlier Bronco II tach that might work.

I'll have to look into it.

 

[410Fortune]

um check the link right above your post

hahaha just teasin

I have 4 ea Bronco II and Explorer Gen I instrument clusters at my house with all sorts of other spare parts and faceplates.
I jsut have not gotten around to this yet but it would be a nice cold weather project.

The race is on! hahaha kidding
let me know what you find out if you find out before I find out

 

[RatStang]

Ok people here is a tech tip.
Or Tach tip if ya like.
Dont waste your time modding your tach.
Go to the wrecking yard and pull a tach from a fullsize Bronco w V8.
Swap the electronics and faceplate and put er back in.
Works great and no errors to play with.
Total cost:
10 Bucks and 2 hours.

Story over.

 

[410Fortune]

Nice

 

[MoabB2]

Sweet!

I'm gonna go collect a few of these big bronco v-8 tachs from the JY and start selling them for $50 bucks a piece.

Hey, that dude on V-8ranger.com sells his module for $70....I'd make a killing!

That's good information to have though, I hope it helps some others who do the V8 swap.