After coming home from a show Saturday when I shut my car off I noticed that all of my Fuel/Temp/Oil gauges were all still reading as if the car was running. My aftermarket radio which I have connected into the accessory terminal on the fuse block was also playing and nothing turn off by the key. I unplugged the Harness to the column with no change. I took it for a ride and noticed my oil gauge was erratic going up and down. I have a lot of stuff unplugged with no change. I will remove the cluster next but does this sound like my voltage limiter is bad and backfeeding somehow or maybe my oil gauge has went bad or shorting out as all the gauges are fed together. Sorry for the long post. Thanks, Lou

something is powering the gauges and radio, but it doesn't sound like it is the dash doing it.
most of that key's off with the car.
so you should trace where your wiring is common, or run a few tests on the ignition switch to see if it is bleeding over.
this isn't the time to pull the dash apart yet.
you have to find out where the power is coming from first.

How old is the wiring harness?
If you pull all the fuses does it still have a problem?
Are the large red and black wires behind the fuse block burnt or starting to show signs of over heating?

I have the column completely disconnected and still have the problem. I Take out the fuses one at a time and the only change I get is when I take out the fuse to the rear harness which obviously cuts out the fuel gauge. The harness is original. I haven't taken the block off of the wall yet that might be my next move. I am getting a back feed or short from somewhere which is why I was wondering if it could be the oil gauge or limiter.

The original harness probably has seen it's day and needs to be refreshed/replaced.

On the 70's I think you take a hex headed screw off of the corner of the fuse block on the fuse side and then push the clips in to slide the fuse block off of the bulkhead connector. Some years had the screw others did not.

The fuse block will reluctantly pull away from the bulkhead harness to allow you to inspect the wires behind it. If you can see the wires going into the ammeter that is another good sign of the condition of the harness.

The Large Black and Red wires are from the engine compartment that go to the ammeter and power the harness. They frequently burn and cause power shorts where stuff that shouldn't get voltage gets voltage. I had one where the park/side marker lights would not turn off but I could dim them with the dash dimmer. Funny stuff sometimes.

If you need to rebuild it, it is pretty easy to do.

Pulling the dash makes it easier but I have removed the harness with the dash in. I have even rebuilt the harness in the car. Basically you carefully unwrap the harness and follow the main power wires until you see what they melted to. Fix that wire and replace/repair the main wires. I prefer to replace them with slightly larger gauge wire and run the new wires to pass through terminals rather than back into the bulkhead connector.

Let me know how the wires look.

Well tomorrow is a new day we'll see what I uncover when I take off the block. Thanks for the replies!

There is no fuse between the fuel gauge and the rear of the vehicle. The only fuse in the fuel circuit is the one that feeds the IVR (instrument voltage regulator). The IVR feeds the + side of the fuel gauge and the sender is hooked, with no fuse, to the - side of the fuel gauge.

Sounds like you have a short and the fuse you pulled is the circuit feeding that short.

This is what I found. Black feed wire was shorted against the Green wire and the White wire above it. Green wire feeds the rear harness which has the gas sending unit which I hope was causing my back feed.

Block has slight melting but should be savable. I will have to get some heat shrink to cover the damaged wires.

You will likely want to replace that entire black wire or a section of it. It will come back to haunt you if you don't. Clean and inspect both ends of the red wire going to ammeter as well. You are pretty lucky up to this point not to have a complete melt down and possible fire.

What 70gtx440dana said is correct. You have experienced the smoldering before the fire.

Now is time for Good news/bad news.

Good news you know the problem but the bad news is that it it probably isn't just at that spot. I can almost guarantee that the end of that black wire where it attaches to the ammeter is starting to show overheating also. The wiring needs to be disassembled and checked.

I have in a pinch run a second wire alongside the original black and red wires inside the harness to take the load off them and prevent it from melting further. That works but to really repair the car right it needs to be pulled and replaced. See note 4 below

A few notes from my experience.

1. Lots of people will tell you to ditch the ammeter and swap to a voltmeter. I have never done it and after repairing the harness correctly never had a problem on dozens of cars. The Key is to make sure the wiring and connections are good and the insulators under the ammeter nuts are good. They degrade with heat and the bad wires/connections cause the heat that degrades them.

2. Place a larger than OEM wire in the harness to replace the Original Black and Red wires. Do this in the engine compartment and under the dash. Do not go crazy but at least 1 size larger.

3. Make sure that you use a fusible link at the Starter Relay junction to the main harness. I like to place on on the alternator also. Harness damage is caused by too much current and bad connections. If the Voltage regulator goes bad and sends the alternator into runaway mode, it happens a lot, all that extra current it is putting out will load the wires almost as bad a dead short in the main harness. The Fusible link at the alternator isn't required but is an added measure of safety.

4. Do not run the wires through the original bulkhead connectors. That is a known bottle neck. Those blade terminals are not good enough for the current flow. I use a pair of bolt in pass through terminals. It will not look OEM but it will not fail. When I can't get a good terminal I put the wire through a grommet and solder the engine side wires to the dash side of the wires. Shrink wrap and done.

If you have never pulled a dash it is not hard at all. Let me know and I will walk you through it.

Now that you mention it I had a voltage regulator go bad towards the end of last year and I had no choice but to drive it for a mile or so with ammeter bouncing between normal and pegged before I could pull over and disconnect the alternator and drive home on the battery. I thought I was ok but apparently the damage was done. Not a problem pulling the dash in fact I already have the corner switch bezel out looking for pinched wires so only about 8 more screws and the cluster will be out and I can check the connections then and decide my next move which for now may be just running a new wire beside the old one instead of splicing in a piece.

I would pull the whole kit and caboodle. It is about an hour or less if you have had practice.

1. Remove the battery cable from the battery.
2. Pull the harness Connectors on the engine compartment side of the bulkhead connector. Squeeze the tab(s) and wiggle / pull them free.
3. Remove the 2 speed nuts on the side of the bulk head connector (Engine Side of firewall) and if necessary remove the screws that hold the bulkhead connector to the firewall.
4. Disconnect the Vacuum / multi-hose connector and the cables from the A/C Heater Controls under the dash.
5. If you have Vents with cables attached to the center of the dash under the ashtray remove the screws and let them hang. I put the screws back in the holes they came from.
6. Pull both kick panels and disconnect the door jamb wire switches & the Parking brake switch.
7. Disconnect the rear harness connector(s) located under the drivers side kick panel.
8. Disconnect the dimmer switch wiring at the switch. Often it is melted to the switch so it may be easier to just remove the screws holding the switch to the floor.
9. On 70/71 E-bodies with the under dash trim panel I prefer to remove it from the dash so I do not break it moving the dash around. Several screws along the panel and the wire to the map light are all it takes.
10. Under the passenger side of the dash remove the wires to the blower motor resistor from the resistor.
11. On some models there is a A/C duct that runs under the column, remove it. For the 70 E body there is one screw at the end and one near the middle. IIRC It will slide off the AC box duct.
12. Disconnect the taillight Brake light switch located at the pedal assembly.
13. Pull the clutch pedal switch wiring connector if you have one.
14. Pull the flasher unit on the side of the brake pedal support or disconnect it.
15. Pull Steering column completely or at least drop it down:
a. Detach any shift levers (Column Shift or 1970 Interlock linkage) from under the hood
b. Disconnect the Wiring Harness connectors under the steering column.
c. If you are removing the column rotate the steering wheel so you can get a punch in place to drive out the roll pin in the flex connector at the steering box. To separate the flex joint from the steering box I use a pickle fork to PRY- DO NOT HAMMER the coupler loose.
d. Unbolt the lower support at the firewall. The three bolts to the outside of the large semi triangular plate. Do not remove the 2 at at the very bottom of the column that bolt to the small plate to the large plate. It won't hurt but it won't help.
e. Unbolt the lower support under the column so it drops down. There will be some long studs with nuts and wired washers on them, these are the ones to remove.
f. If you are removing the column wiggle it out of the hole in the firewall, otherwise let the column drop down. as far as it will naturally go.
16. Remove the 4 bolts at the top of the dash at or neat the defroster ducts. Sometimes you will need to remove a speaker panel (71 and later B-Bodies) to get to the bolts.
17. Loosen the two bolts at the ends of the dash in the door frame that were covered by the kick panels. Do not completely remove them just back them out about 5 or 10 turns. when replacing he dash sit the dash on the screws and roll it back into place.
18. Place some blankets on a large flat place to lay the dash assembly on for cushioning. Roll the dash towards the rear of the car and lift it out of the car. Place it wiring side up and got to town.

That's from memory so anyone else feel free to chime in if I missed something.

It is so much easier to remove the dash than to fight the harness in the car.

Since I was there I pulled the cluster and the good news is there is no heat damage or discoloration on neither the red or black terminals and all wiring looks good and pliable so all the damaged was confined to the block and out about 2 inches. Now to decide on my next move I can simply repair the lesser wires and replace the damage wire from the block to the ammeter and be done with it but obviously the block is the weak point. Unless someone knows of a smaller terminal block I have looked up pass through terminal blocks but most of them need 2 one inch holes drilled for them and there is not a lot room on this firewall to do that but I could drill a smaller hole with a grommet and use a surface mount block in the engine compartment. Thanks for all the replies, Lou

Doesn't look that bad. You could replace the harness. I would heat shrink repair the wire and check/clean the connections. However take it a step further. One you can do the Nacho suggestion and run a parallel wire from the alt, through ammeter and back to the battery. Second you could run a larger wire from the alternator around to the starter solenoid, effectively bypassing the ammeter. Current takes the path of least resistance. This will cause the ammeter not to work properly, in which case you'll want to convert to a voltage meter. There are a couple how to's on the board to remove the ammeter from the rallye gauges and insert a Sun or Bosch voltage gauge into the cluster. It looks almost stock.

black wire is pretty much alternator wire to ammeter, with the main splice in the middle

green wire pretty much gets a red trace and is the horn wire.There is no a green wire between bulkhead and rear harness. Rear harness get a dark green wire but coming from turning switch ( for high intensity filaments for turning/hazzard/brake lights on one side )

white wire crosing over both wires on pic there is the source for backup lamps running to NSS on transmission. It comes from accesories side of the fuse box. If white and black wires meet together on a peeled off area sure all the accesories will be constantly feedback sourced no matter the ign key position, since ammeter network is a constant batt source.

Actually there is not a short here, but alt wire melted by the excess of amperage running thought the bulkhead. Pretty much due the tipical unneficiency of stock alternators, which make them to get more sourcing when revving up to fee dthe car demands and get the batt recharged. The heating point begins on packard terminals on bulkhead hence why most of Mopars gets these cavities melted down.

bulkhead conection is available new.