Topic: 79 Trans am Clock

[mattblack84]

Hi all !  I recently rebuilt my tach and bought a new clock in my 79 Trans Am.  The problem i'm having is now it only works with the car running any body else run into this?

[b_hill_86]

Would have to imagine it’s power wire to the clock on the plug on the back of the cluster. Happen to have a wiring diagram? Seems to me on my 77 there is a dedicated wire for the clock on that plug if I remember right.

[Wallington]

The tacho will only work when car is running...yeah, ok leaving now!

[mattblack84]

No the clock will only work when running LOL  There is a separate wire I was seeing if someone else had replaced the clock inside there tach.  If i find it i will post a picture so that if anyone else wants to buy the clock only they won't make the same mistake i did.

[b_hill_86]

If you have a diagram you’ll be able to figure out what wire is power for the clock on the plug that goes into the cluster. I don’t know if it’s the same for 77 and 79 so I don’t want to tell you the wrong pin location. I’d start there.