hooking up a tach to a '98
Junior Member
Joined: Jan 2004
Posts: 7
Likes: 0
From: St. Louis
ummmm
I just installed a remote start on 98 auto and found there to be no tach wire in the dash (makes sense since there is no rpm gauge on the dash) But lucky for me the unit I was installing has a smart mode that does not require a tach wire and that is what I used and it works perfectly. From my understanding you can pull a tach signal from the PCM which is under the battery.
Scott
Scott
Senior Member
Joined: Feb 2002
Posts: 204
Likes: 0
From: MADISON, WI
Mike
I also have a '98 with the 4.6. I installed an aftermarket tach.
I obviously figured the same thing you did - there is no easy to do it. I did the installation ran the wires and hooked everything up except for the tach signal wire. I then simply took it down to the local Ford dealership and explained what I wanted done. They did spliced into the proper wire and the tach has worked fine now for several years.
Now to better answer your question: As you stand in front of your truck and look into the engine bay, look at the firewall on the driver's side. You will see three bundles of wires feeding through the firewall. The wire that they spliced into was in the topmost bundle (the bundle furthest from the ground) and it was yellow in color. I just looked at it again. The trouble I see is this. I noticed two yellow wires in that particular bundle, and can't really notice any difference between the two. I will be first to say that I am not a mechanic by trade.
For me the choice was simple - just let the pros do it. If I recall correctly, they charged me .25 hours to do the wire splice.
Just on additional note: the first Ford dealership I called claimed to have no idea of how to do that install. The second and much larger one had no problem with my request. If I were you, I would do the install myself and save that money, then call around to some dealers.
Bottom line is this: we both know that several models of '98's had factory tachs. The wire the my dealership spliced into was undoubtedly the wire that would have run to the factory tach if the truck had come with one.
I also have a '98 with the 4.6. I installed an aftermarket tach.
I obviously figured the same thing you did - there is no easy to do it. I did the installation ran the wires and hooked everything up except for the tach signal wire. I then simply took it down to the local Ford dealership and explained what I wanted done. They did spliced into the proper wire and the tach has worked fine now for several years.
Now to better answer your question: As you stand in front of your truck and look into the engine bay, look at the firewall on the driver's side. You will see three bundles of wires feeding through the firewall. The wire that they spliced into was in the topmost bundle (the bundle furthest from the ground) and it was yellow in color. I just looked at it again. The trouble I see is this. I noticed two yellow wires in that particular bundle, and can't really notice any difference between the two. I will be first to say that I am not a mechanic by trade.
For me the choice was simple - just let the pros do it. If I recall correctly, they charged me .25 hours to do the wire splice.
Just on additional note: the first Ford dealership I called claimed to have no idea of how to do that install. The second and much larger one had no problem with my request. If I were you, I would do the install myself and save that money, then call around to some dealers.
Bottom line is this: we both know that several models of '98's had factory tachs. The wire the my dealership spliced into was undoubtedly the wire that would have run to the factory tach if the truck had come with one.