No Tach?

[Justink]

Well it works, except for when I turn on the gauge lights, then it just stays at 1000 rpm, regardless of actual rpm. All of the other gauges work fine. Tried pressing on cluster and nothing happened.
Any Ideas?
1984 Culass supreme. factory tach

 

[88hurstolds]

It's the circuit board on the reverse side of the cluster, you have a bad connection causing the gauge lights to interfere with the tach or something along those lines. I'd also solder the 6/8 cylinder jumper connection for the tach while you have it out.

 

[Justink]

Ok thanks. How do I fix it? Or will the bad connection be obvious?