how do i make the tachometer work in my truck?

[stamina]

when i did the 4.0 swap i installed a 92 explorer engine harness and my truck is a 90 ranger so i left the dash harness in place. the connectors ended up being different and i tried a few things but nothing worked. as of the first time i ran my new motor, the tach did not work. i had oil pressure and water temp on mechanical gauges, my fuel gauge worked properly and my voltage gauge was not working at all. the truck didn't move so i don't know if speedo worked. how do i make the tach work? obviously the most simple answer is to get the 92 explorer dash harness but i would like to at least get the tach working til then. the radio and blower motor also dont work

 

[franklin2]

Do you have a darkgreen/yellow stripe wire at your instrument cluster going no where? If you do, take that and hook it to the coil - wire and see if it starts working.

 

[ekrampitzjr]

Wait a minute. If the truck didn't move, you've got bigger problems than the tach. Right?

 

[stamina]

Wait a minute. If the truck didn't move, you've got bigger problems than the tach. Right?

yes but those have already been figured out

 

[RonD]

In a 1990 Ranger the tach signal comes from EDIS-6 spark module which was the same on 1990-1994 4.0l engines

On the cluster wiring there should be a black/yellow and tan/yellow wire next to each other those are the tach wires
Black/yellow is a ground
Tan/yellow is the tach signal from EDIS-6

Cab Fuse 17, 15amp, powers the tach..............in 1992 which should the same in 1990 but not sure

 

[Eddo Rogue]

In a 1990 Ranger the tach signal comes from EDIS-6 spark module which was the same on 1990-1994 4.0l engines

On the cluster wiring there should be a black/yellow and tan/yellow wire next to each other those are the tach wires
Black/yellow is a ground
Tan/yellow is the tach signal from EDIS-6

Cab Fuse 17, 15amp, powers the tach..............in 1992 which should the same in 1990 but not sure

My tach wont drop below 3000rpms, and reads high....I checked fuses, connectors, and grounds. Could it be a bad EDIS-6 module?

 

[Blmpkn]

EDIS-6 sounds like some dystopian planet

 

[Eddo Rogue]

EARTH is a dystopian planet.

 

[dvdswan]

EARTH is a dystopian planet.

Actually, its the humans. The planet is fine.

 

[RonD]

My tach wont drop below 3000rpms, and reads high....I checked fuses, connectors, and grounds. Could it be a bad EDIS-6 module?

Does it go to 3,000 with key on or just after engine starts?
No, wouldn't be EDIS unit or engine would run bad or not at all

It could be bad ground wire at the cluster, the black/yellow wire

Could be someone swapped out tach and didn't put the needle back on in the right place
If tach shows 3,000 rpm after startup and RPM is actually say 1,000 does the tach go up and down correctly assuming 2,000 as 0 RPMs

 

[scotts90ranger]

The dash wiring changed in '92, if you used a '92 cluster in a '90 it won't work right, you need an '89-91 cluster. The speedo would work since they're the same no matter what (the second gen is the easiest to keep the stock speedo, it literally just pops out...). Plus who knows what Ford changed elsewhere but I would start with getting the right cluster...

 

[Eddo Rogue]

Does it go to 3,000 with key on or just after engine starts?
No, wouldn't be EDIS unit or engine would run bad or not at all

It could be bad ground wire at the cluster, the black/yellow wire

Could be someone swapped out tach and didn't put the needle back on in the right place
If tach shows 3,000 rpm after startup and RPM is actually say 1,000 does the tach go up and down correctly assuming 2,000 as 0 RPMs

Just after engine starts. I haven't looked behind the cluster yet, but might grudgingly have to. No, it worked fine for a long time then suddenly got weird. It repaired itself for a min, but then got weird again. Yes the tach goes up and down but not proportionately. The higher I rev, the more accurate it becomes. It's just way off at idle/low rpms.

 

[stamina]

Does it go to 3,000 with key on or just after engine starts?
No, wouldn't be EDIS unit or engine would run bad or not at all

It could be bad ground wire at the cluster, the black/yellow wire

Could be someone swapped out tach and didn't put the needle back on in the right place
If tach shows 3,000 rpm after startup and RPM is actually say 1,000 does the tach go up and down correctly assuming 2,000 as 0 RPMs

i found a connector in the engine bay next to the power distribution box, tan/salmon and yellow wire going to it completely by itself, i will be using that to supply tach signal, battery power and ground and only will be using it from the engine bay for the initial heat cycle and oil change before she rolls out, found it in a youtube video, the connector usually has a jumper on it and is usually used for diagnostic things? but can be used for direct tach signals. pretty awesome.

edit: i will be controlling the throttle inputs from the body itself w/ a water temp, tach, and oil pressure gauge also being able to watch and hear everything up close during.