3.2 conversion - the tach works until the lights is turned on
 

Hello great forum!

I have a 74 with a 3.2 from 87 - builded in the US some years ago - now in Europe.
I just had all the gauges out to paint the dashboard.
Now installed again all gauges seems to work, but the tach goes dead when I turn on the lights. The motor still runs, no problems there...

At the terminal switch at the back of the tach I have black/violet in pin #2 and red/black directly below (I guess that is pin #5). However, I have no brown wire (ground) for pin #6 and as far as I know - never has been. There was a loose black wire (not connected to anything) when I took the tach out. I thought this was for the upshift-light and therefore this could (and should) be left hanging.. But I could be wrong.. Could the black wire actually be ground?
How do I check this?
And if so - I guess it goes to pin #6. But is #6 bottom-right or bottom-left?
Is the order: First row: 1 2 3 (last pin not used)
Second row: 4 5 6 (last pin not used) OR 6 5 4 (last pin not used)

(I know it is probably on the back of the tacho - but it is real hard to see...)

BTW: I also had a new Steve Wong chip installed while the gauges were out - but I guess this could not affect my tacho-problem since the engine seems to run smooth?)

Hope anybody has some ideas...

Thanks!

Regards
Tom

You definitely need the terminal 6 Brown ground wire to the Tachometer. I don't have a tachometer to check the pin order for you.
Black upshift wire can be left out.

Thanks E Sully... I will go check tomorrow after work if the black wire is not actually ground. I think it might be - then it is just to hook it up to pin #6... You have to be a little lucky sometimes I guess!
Will check the tach if #6 is to the left or right to #5 - hope I will be able to see it on the back.
Happy driving...

The black wire should go to the DME connector, pin 11, to operate the upshift light.
You need to find the brown ground wire that is shared by the instruments and jumps between.

http://forums.pelicanparts.com/uploa...1395608037.jpg

Tom

What Ed said and a photo or two of your car :)

Welcome to PP and the madness.

I will get that sorted asap… Won't make it today after work though.
Here is a picture of the car - but I am in the progress of changing several details in and out - will post pictures when finished.
Thanks for the help and welcome

Tom

http://forums.pelicanparts.com/uploa...1395646165.jpg

Checked the black wire today. It turned out that it was actually ground. So I hooked it up to terminal #6 and fired the beast up. Everything works now!
Great - thanks for your help Ed.

Tom

Great, we need a front shot :)

holy cow, that is a sweet ride.