Tach Not Working - Need Wiring Help
 

Since my winters work in the car my tach seems to have stopped working. I removed the HVAC system along with a lot of other stuff, so the wiringf could have ben disturbed.
On the engine harness into the ECU there is a red modular plug that has 2-3 wires goingf to it. It is not connected to anything. Could this be my problem? Tryaing to work back from the ECU.

TIA, John

85 1/2 has a small flat plug that the tach signal goes through. It is on the harness near the DME.

Ok, finally working on this. Can you tell me which connection coming out of the ECU is for the tach?
The 1st picture is from the ECU, the second picture is of a connection coming out of the harness behind the tach.

None of those, look for a four pin connector. On 87+ the plug changed. Your car year is 85.5?

Huh. Is it in the engine harness going to the ECU? Yes it is an 85.5.

Thanks for the help.

That is a plug that comes off of the DME harness. That is the passenger foot well in the background.

DAmn, thewre are no other plugs on the harness coming from the ECU. There is a red square male plug with two wires and the white two wire one.

That sounds like it, the Turbo has four wire, the NA has two,

Thanks, will give it a try.

Could be the tach itself. Mine had an electrical component that just burned up.

I had the same issue with my 87NA. The plug shown in this pic was the culprit that I cut out by mistake. The white-w/green stripe and green w/black stripe were the wires (coming from the ECU) that make the tach work. I thought I was careful as I hacked wires. I would hack and then make sure the car would crank and then hack some more. When I was done the tack was inop... Between this post and my Haynes wiring diagram I got her fixed up.
Hope this helps somebody
Cheers
Randy

https://rennlist.com/forums/members/...wire-plug1.jpg

Thank you for this photo of the red plugs !!!
 

For two days I have been stumped by my gauges not working - I found this by doing a photo google search & sure enough, I neglected to connect this one !!!

I feel Like Elvis after this - :rockon: :thumbsup: :cool: :burnout: :atwhore:


Again many thanks to the dedicated fans of these cars, I have never been so happy & now ready to go tear it up in a test drive - then i get to:

strip to bare metal, seal, bodywork, prime, bc/cc & get all of the interior & glass out of storage...

Then sell her & do it all over again !!!!! but next time will be a 100% complete resto or maybe a track car !!!!!!!!!!!!


Respectfully, Nick-Ricky