Dash Lights

[ragtopfury]

So in an effort to keep from having this problem, we installed all new dash lights and sockets when we rebuilt the dash in Jake's 65 B'cuda. We are getting ready to fire the beast up for the 1st time and want to make sure all the electricals are good before the initial start up. Going thru everything, we have power to all exterior light sockets, dome lights are good, stereo is good - but the dash lights do not work at all. I expected the dimmer switch funtion of the headlight switch to be an issue, but we don't get a high beam indicator, turn signal indicator, or an oil light, let alone the cluster lights themselves. Other than the oil light (was disc when we got the car) most of the dash lights were functioning before the tear-down 2 years ago. So my quesion is, now that the dash has been cleaned, painted and is back in the car, where does the cluster pick up it's ground? That's my best guess on where the problem lies. I dropped the column last night and am just about ready to roll the cluster out to get behind it.

 

[tekslk]

I think its grounded to the firewall.

 

[RedFish]

Its grounded at the hardware that holds it in the dash. This applies to all metal instrument housings. The later plastic housings do have a actual ground wire in their harness.
With enough paint you could interrupt that chassis ground path. A dedicated ground wire is highly recommended.

 

[67Dart273]

A dedicated ground wire is highly recommended.

X2. Connect a ground pigtail to one of the mount screws for PC board ground. If you follow the traces, you can easily see. Run a wire over and bolt it -- I used the column brace.

The oil and brake warning light should work without the dash grounded. The brake warning light gets ground when the brake warning switch "makes" OR the emergency brake is pulled out so you can check that

The oil light works when the oil sender "makes" and grounds the sender wire, so you can easily test it.

The high beam, like the dash lamps, needs a ground

You can check for power at the instrument fuse. With light switch in park or head, the fuse should have power on both ends, ONLY if the dash dimmer control is twisted to "bright." That fuse is BETWEEN the dash dimmer and the lamps.

The dash circuit gets power from the tail / park circuit, so they must work first.

 

[ragtopfury]

So I ran a dedicated ground, cleaned all the contacts on the circuit board, found 4 of the pins where the harness plugs in were way loose - soldered them in place. Looks like we're good to go now! I think the biggest issue was the loose pins.