Tach Wiring

[emunder]

Evening fellas. Trying to get my tach working & I've done a lot of reading but none of this is getting through to me. I have the inline 6 and the dash has a stock tach there but it's not working. From what I have read I need to locate the green & yellow wire & hook that up to the coil? Can any of y'all identify which is the green/yellow wire I am looking for in one of these pics? And if so what do I need to do from there to get it hooked up? This is probably way easier than I think but it's not making sense to me. Any help would be greatly appreciated.

[Gary Lewis]

If your wiring is original then the wire will already be hooked up.  You can see it in the diagram below coming off the right side of the coil:

[emunder]

Is this going to be the wire Gary? If everything is plugged in I wonder why it doesn't work.

[Gary Lewis]

That should be it.  

[ArdWrknTrk]

Nice to see a Wix/Dana oil filter on there!  

Your engine looks amazingly unmolested.
Are you sure someone hasn't swapped in a tach cluster where there wasn't one before?

Otherwise I might try following the "goes to EEC" diagram in the EVTM that Gary posted a page of.
Sometimes connectors get a little fuzzy and they just need a little De-oxit and being replugged.

The engine wouldn't run if the computer couldn't break ground on that green wire, so it must be between the computer and the tach in the cluster.

[emunder]

I like them, use them on all my vehicles.

[ArdWrknTrk]

If the EEC didn't get a tach signal the fuel pump(s?) would shut off after a couple of seconds.

One of the signs of a bad EEC is if the pump runs continuously.

[emunder]

I feel like a complete dumbass...#18 fuse was blown. Replaced it and now the tach works like a charm.

[ArdWrknTrk]

Simple fix is always nice!  

Wish my truck was that easy.

[emunder]

I hear that man. Normally things don't work out this easy lol.

[Gary Lewis]

Good job!  

[ArdWrknTrk]

You know? I was eyeing the #18 fuse when I hooked up my foglamp switch....
But decided against it because the '87 has no ICVR and All the gauges run off it (except the mechanical speedo)

Those Superbright LED's make a huge difference over 917's (or whatever the wedge base bulbs are)
But I still didn't find the problem with my parking brake light.  🙁

[emunder]

When I replaced the #18 fuse my e-brake light started working again. Also activated the emissions light but at least that's off lol.