69 rally gauges not working - where do I start

[69customS]

So I got this great 69 custom S off of ebay... rebuilt motor/trans, suspension done, new radiator, new everything really..... guy was great at mechanical. Then there is the electrical.... 

He was not so great at that. The tach that was in it was the wrong one... and he had a replacement for me which I switched out and it works great. The rally gauge cluster however.... does not. Its the one that has the gauge for temp, oil, and fuel, with the gen light at the bottom. I pulled the entire dash apart and made sure the circuit board (new) was on there correctly and all tight, the ground points were all attached and tight, and even added a few ground wires just in case. The tach and the speedo work fine.... but the last cluster does not work at all. I see the oil pressure move a little but everything else pegs out and stays there (car off or on). 

 

I would like to bench test this but do not know how to do so. If anyone knows the proper way to test I am all ears. I have a meter and plenty of resistors or a dc variable voltage power supply I can use to test. 

I really like how this gauge looks and dont really want to get a repop... any advise is welcomed. Thanks. 

 

Looks like the picture attached.

[69customS]

Solved!!!! I'm going to start another post telling what I found out and how to get your rally gauges going.

[Frosty]

Can't wait to see what you post.

[69customS]

 

[360Rocket]

I had the same thing with my oil pressure, pegged out. Thought it was the oil sending unit but no, I found a wire going thru the firewall grounded out.