gauge cluster lights and others not working

[challenger_affair]

My gage cluster lights do not come on, nor do the console light or the dome from the passenger door.  Tach and clock are not working either.  These problems may or may not all be related, but the radio has been removed and I notice there are several connections unplugged so I wonder if any might be important.  See pictures below.

First pic shows two connectors in the center of photo.  From the wiring diagram, the black connector with the orange, orange, blue, red wires might be in the cluster light circuit.

Second pic shows two connectors next to the steering column

Third pic is the fuse block.  I tried putting a fuse in the empty spot but it didnt seem to change anything...

My understanding of electrical is limited so any suggestions are appreciated. I can't drive at night without the gage lighting and it would be nice to know if the malfunctioning instruments was only due to some connection issues! 

[72cudamaan]

I would start by removing the fuse block and cleaning up the corrosion (green stuff) in it. You
may have a bad contact to the fuses. Did you just take the radio out ? If not, I wouldn't think any of
those connectors are the problem. Though I guess one might have vibrated loose. Before you take the fuse block out, you might
try using a test light on each side of the fuse to be sure that you are getting continuity across the terminals.

[Jamiez]

If the dash lights and dome light are not responsive, I'd bet on the dimmer being bad.  These seem to be a problem on a lot of cars. Slotts of JS Restorations sells new ones and will take your old one as a core.  Doesn't take long to do the swap.

Not to point out the obvious, but you are definitely missing a fuse as well...

[challenger_affair]

Thanks for the suggestions.  I didn't remove the radio, previous owner did some monkeying around trying to install a new stereo which is no longer in place either... 

Don't hesitate to point out the obvious, I'm generally lost with electrical; although I did point out above that I placed a fuse in the vacant slot and nothing changed...  Perhaps that is due to some corrosion as 72cudamaan suggests. 

Dumb question about testing the fuse connection, would I use a test light with the ignition ON, or a self-powered continuity tester?  and would I connect the clip to ground or one end of the fuse?

[72cudamaan]

Yes, key on and test light to known good ground. Usually the ign. key or door jamb switch are good grounds, but
test the light on a good known connection first. No sense in looking for a problem that may not exist.

[challenger_affair]

Well the continuity test worked.  There's no continuity across the fuse for 'instrumentation' on the top right even after replacing it.  Also filled the empty slot on the bottom right... 

There's an orange wire sticking out from behind the top of the fuse block that looks sort of out of place but I can't see either end.  I'm tempted to try and pry the fuse block loose and see whats behind it.  does that sound like the next logical step?  Do I need to disconnect the battery for that operation?

[dodj]

Well the continuity test worked.  There's no continuity across the fuse

The fuse blew when you replaced it, or am I misunderstanding?

[challenger_affair]

No the fuse did not blow.  I don't know the reason for the lack of continuity. 

[72cudamaan]

No the fuse did not blow.  I don't know the reason for the lack of continuity.

If you don't have continuity across a fuse, it is obviously bad. Unless it blew as soon as you put
it in. Then you have a dead short.

[challenger_affair]

It was a brand new fuse, and the one I replaced looked fine also.  I can try another new fuse though...  I'm having trouble getting a good view behind the fuse block, I guess all the connected wires make it difficult to rotate.  Is there a good way to check this?  Or is there some other test I can do to try and isolate the problem?

What do you mean by 'dead short'? 

[72cudamaan]

It was a brand new fuse, and the one I replaced looked fine also.  I can try another new fuse though...  I'm having trouble getting a good view behind the fuse block, I guess all the connected wires make it difficult to rotate.  Is there a good way to check this?  Or is there some other test I can do to try and isolate the problem?

What do you mean by 'dead short'?

You should be able to check continuity of the fuse without installing it. Do that first. Don't go taking the fuse block apart until you know where the problem lies. A dead short means you have a bare hot wire laying against a grounded surface, so when you install a new fuse it blows immediately. If this is the case then you need to find and fix that first.  Keep trying...you'll make it.

[challenger_affair]

Thanks for your suggestons.  The problem is I don't have the electrical chops to know how to go about testing for a short like that...  If there's no continuity across the fuse, and the fuse is not blown, would that point to the panel dimmer as Jamiez suggested?  How could I test the dimmer? 

[72cudamaan]

Thanks for your suggestons.  The problem is I don't have the electrical chops to know how to go about testing for a short like that...  If there's no continuity across the fuse, and the fuse is not blown, would that point to the panel dimmer as Jamiez suggested?  How could I test the dimmer?

When the fuse is in place, you should show power on both sides of the fuse. If you don't have power on both sides that would mean that
you have a contact problem in the fuse block. In which case you would have to take it apart and fix it. Hence the need to clean the green crap off of the contacts.
Make sure you disconnect the battery before you start messing with pulling the fuse block. Do you have a service manual. That would be pretty important to trace your wiring. It will also show you where the wiring leads to so that you could start at the end of the circuit and keep back tracking until you find power.

[challenger_affair]

I have the service manual but the details on dealing with the fuse block seem slim.  All those wires and limited accesibility, looks like a nightmare task to tear into that thing...  Do I take your comment to mean this is the best place to start for this problem?

[HP_Cuda]

Not to hijack this thread but I think this might be a useful question as well.

I'm about to put my dash back together and I'd like to test all the switches/knobs before putting it back in the car. I have a 12V powersource and multimeter/cont tester so I should be able to see if it works properly if I know the pinout of each switch/knob.

Has anyone does this?

Thanks,
Bryan