I have a tachometer that is not working. Where is the connection end at the motor? Sorry book does not show it.

All other instruments work, tach does not have back light.

 

Look at page 26 in this link. You can see it there in the middle of the diagram, two different spots that say "to tachometer". I don't know why they have two different options, I thought most of the time it was on the coil "tach" terminal. There is a splice out there in the distributor/coil wiring.

Start & Ignition - ???Gary's Garagemahal

 

You are looking for a connector near the DS2 ignition box on the left inner fender well.

If you have a V8 engine the connector will have 2 wires one each side of the connector, one black wire and one green wire.
If you have a inline six the connector will have only the green wire on the engine side of the connector The following photos are of a six cylinder engine.

In the first photo you can see the single green wire in the connector, near the middle of the photo.


In the second photo the connector is in the top of the photo.


Jim

 

I think those two different spots are actually the "ground" and "signal" wires, if I'm reading the diagram correctly. But the signal does originate from the negative coil terminal.

 

What Engine do you have?

You are looking for the (DG/Y D) Dark Green with Yellow Dotted wire coming from the Breakerless Ignition Module. (Primary - Tach wire)

The Black/Light Green Dotted wire in the diagram is a ground wire.

 

I believe you guys are right, they are using that ground out there instead of one in the dash.

 

FYI - 1980 EVTM







FYI

 

Boy, the wiring diagrams from the 80 model year sure looks "clean" compared to the later models. My philosophy is the "simpler the better" to bad Ford didn't adopt that philosophy too.

 

I have the 300 I 6 motor. All the smog has been disconnected. I found the last vacuum line on the carb that was causing rough idle. Runs real smooth now. Still smokes a little...

Thanks for all the info!!

I will see what I can find on the tach this morning...

KB

 

Feels good when something goes right don't it, running smooth.


What does your tach go up to being you have a 300?
I would love to add one to my truck with a 300 also but the v8 tach reads too high.


There was a post not long ago of a member buying one with lower red line and getting it to work, little more work than I want to get into at this time.


Funny mine also ran ruff when I got it, new plugs and it ran smooth
and 10 min later I pull the truck all apart!
Dave ----

 

I think all these loose connectors are smog. The tach is on a circuit board with other instruments. Maybe I will pull it loose...

 

The ground in the engine harness is used in a V8 engine installation only. The Tach uses this extra ground as a "calibration switch" so it can read correctly, for either V8 or six cylinder engine.

In the photos I posted,, you can see there is no ground wire on the engine side of the Tach connector on my inline six engine DS2 harness.

Jim

 

The Tach connector is shown in the first photo, upper left corner under the larger plug.
It has 2 wires on one side and 1 wire on the other side,
It looks like it is connected, so if the engine wire good I would look at the Tach circuit board.

https://www.ford-trucks.com/forums/7...dywhompus.html

 

0-60 (6000) rpm tach on circuit board.

 

Thanks
Dave ----