66 BB Identification Panel Lights do not light except for the a/c pull panel light

[Harry L.]

All gauge lights work. The a/c pull light works, but all other identification instrument panel lights do not light. They used to come on periodically. Now they never come back on. There must be something that must have disconnected. Can someone give me some suggestions as to what my problem could be? thanks. Dutch

[John H.]

Re: 66 BB Identification Panel Lights do not light except for the a/c pull panel ligh

All gauge lights work. The a/c pull light works, but all other identification instrument panel lights do not light. They used to come on periodically. Now they never come back on. There must be something that must have disconnected. Can someone give me some suggestions as to what my problem could be? thanks. Dutch

Dutch -

The two "torpedo" lamps for the two A/C control knobs are part of a separate wire assembly that plugs into a cavity in the fuse block (the single center-mounted one for the two heater control knobs is part of the dash harness). See your Assembly Manual, section C60, sheet E8, View "A".

[Richard M.]

Re: 66 BB Identification Panel Lights do not light except for the a/c pull panel ligh

The lower heater indicator lamps are the same circuit as the gauge lamps IIRC, so I'd suspect the torpedo lamp sockets for the heater control indicators have lost their ground. I think the sockets for those get their ground from the metal slots under the clock......I think.

Or the heavy ground wire(blk/white IIRC) where it attaches to the underdash Z-bar has become corroded.

All this coming from faded memory as I think about similar problems I've had in the past.

Rich

[John H.]

Re: 66 BB Identification Panel Lights do not light except for the a/c pull panel ligh

The lower heater indicator lamps are the same circuit as the gauge lamps IIRC, so I'd suspect the torpedo lamp sockets for the heater control indicators have lost their ground. I think the sockets for those get their ground from the metal slots under the clock......I think.

Rich -

The clock bracket isn't grounded - it's just riveted to the fiberglass dash panel. The torpedo lamp sockets are grounded by the upturned curved end of their retainer clip touching the clock case, which is in turn grounded by the clock's ground wire in the clock connector. The clock must be installed and connected in order for any of the torpedo lamps to work.

[Joe R.]

Re: 66 BB Identification Panel Lights do not light except for the a/c pull panel ligh

Rich,

The clock bracket should be grounded by the clock itself. The clock is held in the bracket by the two clips in the back. The lamps around the clock bracket for the instrument pulls are grounded by the clock case. Think of it this way, clock is grounded, bracket grounded by the clock installed by the clips and the lamps are grounded by the fact they clip on to the bracket.

JR

[Richard M.]

Re: 66 BB Identification Panel Lights do not light except for the a/c pull panel ligh

Rich -

The clock bracket isn't grounded - it's just riveted to the fiberglass dash panel. The torpedo lamp sockets are grounded by the upturned curved end of their retainer clip touching the clock case, which is in turn grounded by the clock's ground wire in the clock connector. The clock must be installed and connected in order for any of the torpedo lamps to work.

Rich,

The clock bracket should be grounded by the clock itself. The clock is held in the bracket by the two clips in the back. The lamps around the clock bracket for the instrument pulls are grounded by the clock case. Think of it this way, clock is grounded, bracket grounded by the clock installed by the clips and the lamps are grounded by the fact they clip on to the bracket.

JR

Ahhh, okay, thanks for clarifying guys. I knew it was grounded in the lamp sockets but forgot the actual ground point.

So........If he has only the A/C panel lamps and NO Heater panel lamps, it still seems like he lost his ground either at those sockets or lost the clock ground. He didn't say if the clock works or not. He said all gauge lamps work, so his cluster is properly grounded.

We need more info, maybe he lost socket ground, or bad connection at the sockets or burnt out bulb(s) or broken wire to the bulb(s).

Rich

[Joe R.]

Re: 66 BB Identification Panel Lights do not light except for the a/c pull panel ligh

Richard,

The clock has to be installed with at least one clip used. Those are metal and ground the bracket. That is probably what John H. was talking about. The clock not being installed.

JR

[Harry L.]

Re: 66 BB Identification Panel Lights do not light except for the a/c pull panel ligh

As to my clock working is yes and the clock has good light. It is just all the indicator panel lights including the wiper. cigarette lighter, ignition switch, light switch and all other except a/c pull. All other dash lights work. Must be a loose connection. There was a new wiring harness put in 10 yrs ago, but all those panel lights worked for years after that. Dutch

[Richard M.]

Re: 66 BB Identification Panel Lights do not light except for the a/c pull panel ligh

Dutch, All of the lamps come from the gray wires in the harness. It's quite possible there is a break in the harness inside that opens the circuits in some of the lamps.

But......did you actually check the bulbs for those positions? And did you check for voltage at the socket center conductors on each suspect lamp socket? If bulbs are good and no voltage at sockets, when you test them use the cluster for ground, then try a known good ground, like the dash Z-Bar(square tube bar that's behind the cluster, center console and glovebox).

Rich