Just like the title says, i bought a tach for my truck (finally) and now im not sure where my tach wire is....i read up that it is on my ICM but i cant seem to find it! Any info and details helping me to wire up my tach would be helpuful. Thanks

Ive got a 98' 2.5L if that helps.

 

Gimmie a minute I'll find it.... On a side note, how do you seem to have 7000k halogen lights? You were misinformed.

 

You should have just bought a cluster with a tach in it. Much cleaner looking IMO.

 

^^^ Not needed Christian. It's not what he asked.

 

Again IMO. In My Opinion.

 

Right I understand that.... But he wants some helping finding something on his truck and you throw out your opinion. Again, not what he was asking for.

/end hack.

 

Ok. Since I'm the only one that does that right? I'm the only one that adds a post to a thread that doesn't answer or help the original topic. Right.

 

Come on boys. Simmer down now.




Yes....OP should have just got a 98-03 Ranger or Expo SportTrac/Sport cluster that has a tach and swapped it in. No other things needed, just swap in a new cluster, plug it in, and BAM! you've got yourself a tach.

I'm looking in my wiring book right now for your wires to tap into. Gimme some time...

 

I remember doing this on my 2.5L when I put a tach in before I knew about the cluster swap. I'm looking through my books now too.

 

What do your tach instructions say your wires go to??



Its either a Black/Yellow(BK/YE) wire or Tan/Yellow(TN/YE) you need to tie into from behind your cluster. Both those wires are in relation to the tach.

If that's the only place to tie power off of for a tach signal, you've gotta remove the cluster anyway, and since you are doing that, you might as well just swap in a tach cluster IMO.


I'm trying to understand the PCM wires and decoding them to see if you can just get a tach signal from there. Stand by.

 

GOT IT.




Open your hood. Look at the firewall towards the passenger side. There's a big group of wires leading toward it. This is the PCM(Powertrain control module). There is a Tan/Yellow(TN/YE) wire. Tie into that wire for your tach signal.

 

Shane comes through again BAM!!!! Good mod choice IMO.. In my opinoin LMAO!!!

 

Indeed Jer!

 

This might not help but I can tell you this.

I bought a LED/Tach shift light combo for my A-Pillar in my Evo.
I wired it directly to the negative side of a coil and was getting feedback from the ignition causing it to give faulty rpm values at higher engine speeds. I unhooked it from that way and then hardwired it directly into the computer from the main harness and this worked 100X better. If you want to do it that way just find the pinout map for the ECU and jumper into the harness.

 

Shane already found it turb'z. lol

 

i'm a noob surrry... lol

 

Well i dont see any big jumble of wires on my passenger side firewall. I see my brake booster..........and there is a harness right under it that has 4 wires connecting to something right under the brake booster and one of them is yellow/red....but thats the closest i could see to anything you were describing. All the books i have read have said that my PCM is on the passenger side firewall, but all i see is a brake booster and a 4 wire harness.

 

PASSENGER SIDE, not driver side where the Brake booster is located. Your PCM is just right of the heater/airconditioning box on the PASSENGER side of the firewall.

 

 

Would he be able to pick it up from behind the gauge cluster or is the signal modified at that point?

 

I know on my 302 wiring harness, there was an inline resistor for the tach signal that took care of that, I had the same issue before. Also interesting the mustangs tach wire is the same color combo.

 

Most likely.

There's a tach signal coming out of the PCM....wire Tan/Yellow. There's also a wire on the back of the gauge cluster that's also Tan/Yellow and is also in the diagram with the tach gauge. So....yes....I think he can grab a signal from either the PCM or the gauge cluster. Tieing in to the same wire.

 

Nice work comin through in the clutch Shane. Do man things bud

 

Can't really do man things here bud, if you catch my drift....

 

Oh okay, thanks Fx4, ill look there. I was looking in the direct corner on the passenger side. lol and there is a brake booster on both sides of my truck....i see your brake booster on the passenger side of your truck in the picture too :-P