1 - 3 of 3 Posts

1,492 Posts
Discussion Starter #1
My 66 went from the basic guage package & no console, to a full blow option packed dash, all guages & a console, clock etc...

What do I need to do, to convert my existing dash harness, as I do not want to spend the $430 or so to get an M&H or Year One harness...

Is there anyone who has dissassembled thier original, and pieced together a new one? Is the fusebox the same?

When you buy a new dash harness, do you get a new fuse box?

The clips that hold the bus fuses in are all rusted on my fuse box, I'd like to replace them...

Premium Member
2,223 Posts
Yes the harness can be modified to connect to the gauge dash cluster. See the attached picture.

1- The fuel gauge connection doesn't need to be changed.

2- The amp gauge connects to the horn relay, red arrow, and the J-block, yellow arrow. The J-block, junction block, is on the radiator support next to the battery. These wires need to have either 18 ga fusible links or 5 amp inline fuses, the closer to the horn relay/J-block the better. Route the wires through the firewall, be sure to use a grommet.

3- You will need to add a cluster light, lights with gray wires. The gauge dash needs 6.

4- The water temp light gets clipped off and the wires attached to the temp gauge as shown. The water temp sender is available at your local GM parts counter, part # 12334869.

5- The oil press light and 6- The gen light are not used. Remove the bulbs, clip the wires and tape out of the way or ???

You can use tab connectors to connect the wires to the gauges. Ring terminals under the nuts will work also.

The new harness will have a new fuse block. I have read that some use small wire brushes or dermal tool with wire brush wheel to clean the rusted fuse clips.
1 - 3 of 3 Posts