installing tach in 1990 hardbody?

[broncobusterJOHN]

I searched this forum for installing a tach but led to no where with result, what color wires do I need to hook up my tach? wiring schematics? Thanks!

[RT22]

Aftermarket?????? if so hook it up as per instructions hot ground and one wire to coil, not sure which pos or neg on coil should be in instructions with after market tach.

[RT22]

Tobe clear red to switchable hot black to ground and 3rd wire(color may vary ) to coil for pulse. I would assume positive so it can read rpm.

[mrecoolgar]

If it's a Hardbody cluster the wires are there.
Just plug in the tach (and clock) and your done.

[Novajoe]

If it's a Hardbody cluster the wires are there.
Just plug in the tach (and clock) and your done.

if it's a v6 cluster plugging into a 4cyl then your rpm readings will be 2/3 of what they really are and vice versa. This was the case for me anyway in my 97.

according to the service manual for my 97, there are 2 white wires coming from the ignition coil harness. one is ignition signal and the other is tach signal. The tach wire should be terminal no. 3 and should read .9v at idle. The ignition signal should be between .3-.6v. Of course all of this could be completely different from your 90 model.

Most aftermarket tachs want you to splice into the ignition signal wire and adjust the settings on the tach according to how many cylinders you have. if you plug it into the factory tach signal then the readings will be off.

[Drafteddesign]

I installed an aftermarket tach in my '90 hardbody. I just used a piggyback connecter to splice into the wire on the tach pigtail. If this is your situation, let me know. I'll check what color I used, and post