Now that the outer turn signal light issue has been resolved onto the interior indicators.
Again this is on a 71 E body.

No lights working at the light bar for the dash, turn signal indicators in dash do not light up, key light does not light up, console light does not light up.
I checked power to the dimmer switch and I get good power there.
Is every one of these items on the same circuit?
I checked fuses, and all were good.
I checked bulbs in light bar and key light and they look good.

All dash gauges work, including the E-brake light.
Dome light works, and door buzzer works.
Blower motor works
Wipers work
Horn works, headlights and hi beams work

Suggestions on where to start?

A headlight / brights switch failure can cause this, testing the foot switch for continuity would be easy to check.

Really??? Are you saying they ran all of that off the hi / low beam dimmer switch? I'm not questioning your knowledge it just sounds like a strange way of powering things ?
or am I misinterpreting and you are referring to the panel light dimmer?

Also might be a ground issue again.
Need a schematic

Had a late 70s F150 come into shop with a "no lights but runs fine issue" that was a frozen and corroded foot switch. I replaced the switch and wanted to see if I could recreate the issue by holding the switch half way between hi/low, it did.

But if the headlight hi beam switch on the floor is working properly, how would this effect the panel dimmer and other lights?
Are they on the same circuit?

You checked for power at the switch but what about at the bulbs themselves? Most dimable dash lights use an orange power wire.

I think the problem is a grounding issue The above items are grounded through the cluster and frame.

Check to see if the dash cluster & frame is grounded well. I had to run a jumper to a good ground on my old dash since I could never get the grounds to work as it should. My car was just crusty and rusty.

It is very common on cars with age or recent restoration to have rust or paint on the ground points.
There is also a ground wire on the bottom of the steering column to help ground it. I believe it is there since the horn works.



These items work by grounding through the harness or are not tied to the dash/cluster ground and get their ground at a different location.

Typically that would make the headlights inop but everything else is on different terminals of the light switch. I could see a bad light switch, but not understanding how a bad headlight dimmer switch would affect dash lights etc unless it was shorted to ground. Electrically it doesn't make sense

Have you made any progress on this ?

The only thing I was able to do today was check the light bar was grounded properly. I used a test light on one of the screws, and it lit up, so assuming light bar is grounded ok.
I also checked that l had power to dimmer switch plug.
Got power going to plug for switch to black wire.

I'm assuming you are referring to the test light when you say it lit up. So the next step would be to check for power to the light bar.

If you have power at the connector the next step would be to remove the light bar for bench testing.
In the event you don't have power, go back to the fuse box and check for power on both sides of the fuse at the CLIPS

No power present, up to the panel dimmer. No power out?
Check for power in
No power in? back to light switch.

One can also use jumpers to check the circuits / wiring/connections. IE: garb a 12v Source and jumper it to the light bad orange wire. If it lights up you know your not getting power.
one can also Jumper to the input and it should back feed to the other lights. isn't this fun

The screw could be grounded but not getting a connection all the way to the socket where the bulb is. Unfortunately on the E bodies it isn't possible to test the socket on the over guage lights installed, so I suggest you pull the bar and check for positive voltage at the socket then ground the bar with a jumper and check for them to be lighting up when the light switch is turned on and the dimmer is adjusted.

IF there is no + voltage in the socket, with the lights on, then you know the problem is somewhere back in the line, switch, fuse, wiring, etc.

Check the fuses by putting a test light VOM to each side of the fuses with all switches turned off. I have had fuses heat up at the ends and cause the end of the fuse to break contact and still look good in the middle. This usually happens when the socket is corroded. That is why you check both sides of the fuse, to be sure voltage is making it across the fuse to the wiring on the other side. Doesn't hurt to check the contacts holding the fuse for voltage too while you are there.

UPDATE:
As suggested I removed light bar, took out a bulb, put a test light on the bulb contacts and turned parking lights on, and it lit up !
I then turned the dimmer switch back and forth and the test light bulb dimmed and brightened

So the good news, it was a ground issue.
I then scuffed up all the screws mounting the dash light to the frame, as well as 2 of the screws that went directly into the frame, as well as where they contacted the frame.
Put it all back together and presto ! Light bar lights up and dims, as well as the light on the floor console

Thanks for all the suggestions everyone.

Key light still doesn't work, but not a priority right now.

Thanks for the update, many don't which leaves those that tried to help wonder if it was worth the time

The key light could be a bulb, connection issue or once again Mr. ground. just because the horn works does not mean the column is grounded preprly. The horn contacts maybe getting their ground through the shaft itself.
Probe both sides of the column connector for the light with your test light. If you have power, you know where to go next

Thanks TJP.

I tried changing bulbs for the key light.
Will check for power next, thanks !

it's always good to hear a problem has been fixed.

keep us posted and don't overlook Mr. ground. he's a real bas--rd LOL

Yes , yes he is, lol.

No power to the key light, haven't had a chance to get much further, had to move on to other issues.

Not sure on the 71 E's but the 68/9's had a timer that would turn the light on for X amount of time when the door was opened. After X amount of time the light would go out on it's own. The timer was a small round cannister that plugged into the harness under the dash. A schematic would be the next step IMO

What he said. Right there.....

The timer looks like this.

These are the wiring diagrams.

The B sheet has the timer relay in it.

Glad you are on a roll. Hope these help.