RedTop

This started out as me asking how to wire a tach up on my 89 I6 F150. First i tried the Green/Yellow wire behind the cluster but that turned out to be giving FALSE signals causing the tach to JUMP wildly after 1500 RMP.

So Just for fun i ran a temparary test wire from the gauge to the engine and connected it to the wires comming directly off of the coil packs.

Now on my 89 I6 the coil is distributor mounted, some of the 90's f150 put the coil on the drivers side fender where all the wires run into the cab. but the process is EXACTLY the same.

If you find the coil pack and poke around a little you will notice a 2 wire connector thats got factory plug. the plug is REQUIRED so dont remove it. If you do a continuity test n the plug you will see it connects both the wires together.

So i used a BLUE wire splice and tapped one of the plug wires(it doesnt matter which)

After hooking the tach directly to the that connector wire (coil pack -Negative) And started the truck, BAM! tach moves smooth as silk.

Here is a picture of the drivers side ignition components.


By extravagant1 at 2012-07-10

Here is where to hook the tach signal wire

By extravagant1 at 2012-07-13


Hope This helps!

And thank you to all who helped me!

On another note it has a brand new Championship white paint coat, 4 base 3 clear. Picked up some chrome bed tie downs, New chrome grill, Used a kit on the headlights (worked good but not as advertised)

Chrome front/rear bumpers, Fresh window tinting. Now i need to find some Rims/Tires


By extravagant1 at 2012-07-10



By extravagant1 at 2012-07-10



By extravagant1 at 2012-07-10

fordka

Thats a nice solid truck. Your right those wheels will make any truck look borring. You need something like these and a bedliner if your gonna haul anything

RedTop

i updated the orig post with pics of the ignition side and the harness before it runs into the cab

RedTop

Thanks man!

i am gonna do the role on route with hurculiner, since i have read the duplicolor sux

And in my area the closest rhino dealer wants $400 to spray it wo/caps and $425 w/caps sprayed

MattFromKingston

ok heres my 93 so it looks a bit different. my coil is not distributor mounted but i think the wires are the same. right off my coil was a dead plug, one wire of which had the coil negative or signal wire

RedTop

YES! i noticed that also!

Comming off the plug cap there is a 2 wire connector with a factory rubber plug in it.

So thats it eh? the -Neg side of that?

tdcarter72

Ok, I have ran this same wire down in my 87 F-150, which shows to be the same for 87-89 models.

The wire you are looking for is Dark Green/Yellow. It runs from pin #4 on the ECM through a resistor to the Ignition Coil and the instrument cluster. Then it runs from the ignition coil to the distributor mounted control module.

You can make the connection anywhere past the resistor and you should be fine.

Good old Bill

Agree with tdcarter72, dark green yellow hash has always been tach signal wire. The rubber plug in the picture, isn't that the spout connector, used for setting dist timing?

RedTop

Can i connect it right after the plug?

tdcarter72

If it were mine, I would make the connection at the ignition coil instead of the distributor mounted control module.

Find the Dark Green/Yellow wire at the coil and work back 6-8 inches and make the connection there just in case you ever want to do away with the aftermarket tach, you will have enough wire to reconnect it back to normal.