69 instrument panel ground q

[3175375]

While pulling the instrument panel on Shamu, my 69 Fury III vert, I discovered a burnt ground wire that attaches to the back of the instrument panel.

I cut the wrap on the bundle and that burnt wire leads to a splice of several wires.

I plan on replacing the burnt piece, about 3’ long.

Grounding appears to be not documented in the schematic as they simply use the symbol for ground.

Thoughts?

 

[cbarge]

That is not a ground wire as it splices into something else.
Double check in a factory shop manual schematics chapter 8.
Body is ground and there should also be a ground wire at the bolts holding the steering column between the plastic impact thingys.
Hope this helps

 

[3175375]

That is not a ground wire as it splices into something else.
Double check in a factory shop manual schematics chapter 8.
Body is ground and there should also be a ground wire at the bolts holding the steering column between the plastic impact thingys.
Hope this helps

That absolutely is a ground wire.
It splices into the ground wire for the key lamp and other dash bulbs.
Yes, I have the ground wire at the steering column.

I have reviewed the factory service manual.

 

[thethee]

What I believe cbarge meant is that that symbol generally indicates that the unit is ground simply through the housing, and shouldn't have a ground wire?

Which might lead to the next question, are you sure this ground wire and splice are factory? If it's a ground wire it looks like it grounds the cluster, ie the cluster lights. Did those work when you pulled the cluster?

 

[3175375]

What I believe cbarge meant is that that symbol generally indicates that the unit is ground simply through the housing, and shouldn't have a ground wire?

Which might lead to the next question, are you sure this ground wire and splice are factory? If it's a ground wire it looks like it grounds the cluster, ie the cluster lights. Did those work when you pulled the cluster?

The lamps worked and the wire was still connected to ground. Apparently, it got hot and melted the insulation on it all the way back to a weld joint in the harness that was covered with cloth tape under the electrical tape over wrap.
I have verified the wiring and will splice in a new wire near the weld joint. It’s the wire that connects to a spade male that is riveted and soldered to the back of the speedometer housing (ground for turn signal indicators, oil light, etc.).

 

[Big_John]

From pages 8-130/131 in the 1969 Plymouth FSM; I assume by "lower reinforcement" they mean the column support.

Black #18 wire, circuit E10, E10A, and E10B.

I don't see it splicing into anything else besides the hi beam lamp connector though.

 

[3175375]

From pages 8-130/131 in the 1969 Plymouth FSM; I assume by "lower reinforcement" they mean the column support.

Black #18 wire, circuit E10, E10A, and E10B.

I don't see it splicing into anything else besides the hi beam lamp connector though.

View attachment 533478View attachment 533479

There’s 3 connections on the ammeter ‘supply side’ - red mark on the back of the instrument panel.
They are:

Gray wire to the clock connector
2 red wires- one goes to the battery
I suspect that the other goes to the ignition switch?

On the green side, one black wire to the fusebox/horn relay


This is a picture of the wiring before I disassembled/removed the instrument panel (the black wire is removed in the picture).

The ammeter worked before disassembly.

The ground wire that was damaged goes to the stud/male terminal on the back of the instrument panel.

I am going to pull the bulkhead disconnects off and ohm everything out regarding this circuit.
(I have a feeling that the previous owner may have miswired this)

 

[1970FuryConv]

While pulling the instrument panel on Shamu, my 69 Fury III vert, I discovered a burnt ground wire that attaches to the back of the instrument panel.

I cut the wrap on the bundle and that burnt wire leads to a splice of several wires.

I plan on replacing the burnt piece, about 3’ long.

Grounding appears to be not documented in the schematic as they simply use the symbol for ground.

Thoughts?

View attachment 533418View attachment 533417View attachment 533419

1st, I have not done a 1969 Fury instrument cluster. However, I have done a 1970 Fury instrument cluster. That ground wire should not have burnt up unless it got shorted to power somehow. For 1970, that ground wire goes to a connector, 2 spades, that leads to the high beam indicator. One spade of the connector is power to the high beam indicator. The 2nd spade is the wire that burnt up on your car, a ground wire to the high beam indicator and a 3rd ground wire that goes to a lower reinforcement on the body, presumably the dash shell or firewall. All of the ground wires are black. If you're ground wire got shorted to a power wire for the high beam indicator, or some other power wire, it could have burnt up. I would trace down all of the black wires that were connected to the burnt wire and see if I could find any shorts. Furthermore, I would make absolutely sure that there were no wires of another color that were in this junction that the previous owner may have made in lieu of the connector for the high beam indicator lights. Of course, all this is predicated on 1969 and 1970 being the same. Best of luck! Ben

 

[Big_John]

Gray wire to the clock connector

Gonna do this one at a time... From 8-124 in the FSM, the wiring to the clock. There is a black wire from the clock to that connection on the "radio capacitor".

An so we're on the same page, this is the ground connection on the dash at the radio capacitor.

 

[Big_John]

2 red wires- one goes to the battery
I suspect that the other goes to the ignition switch?

On the green side, one black wire to the fusebox/horn re

There is a black wire (#12) that runs from the ammeter to the infamous "welded splice". This would be on the "after" side of the ammeter. I think this is one of the melted wires you have... Or it's already been replaced with a red wire. Hard to tell from the pics.

 

[Big_John]

The other wire (in) to the ammeter runs from the bulkhead in #28 cavity to the ammeter.

 

[Big_John]

Back to the accessory page, there is a red wire that feeds the 15 amp circuit breaker. I think this is either for power windows or convertible top.

 

[Big_John]

The other wire (in) to the ammeter runs from the bulkhead in #28 cavity to the ammeter.

View attachment 533544

And the wire from the #28 runs directly to the starter relay and then to the battery.

 

[3175375]

Gonna do this one at a time... From 8-124 in the FSM, the wiring to the clock. There is a black wire from the clock to that connection on the "radio capacitor".


View attachment 533527


An so we're on the same page, this is the ground connection on the dash at the radio capacitor.

View attachment 533530

Then we’re referencing 2 different FSMs. Page 8-124 in the FSM I have (downloaded from MyMopar.com) is a schematic for Satellites, etc.

Here’s the pages (8-130, 131) that’s for Furys.
However, I am thinking that the plug for the high beam indicator and the clock may be swapped incorrectly.
More to review.

 

[Big_John]

Then we’re referencing 2 different FSMs. Page 8-124 in the FSM I have (downloaded from MyMopar.com) is a schematic for Satellites, etc.

Mine is from MyMopar too. The 8-124 is shown here.

 

[3175375]

Mine is from MyMopar too. The 8-124 is shown here.

View attachment 533576

They both are there. Interesting that the diagrams are different depictions.

Regarding the high beam indicators and clock connections being swapped, not true. They are opposite sex.
More investigation tomorrow.

 

[3175375]

There is a black wire (#12) that runs from the ammeter to the infamous "welded splice". This would be on the "after" side of the ammeter. I think this is one of the melted wires you have... Or it's already been replaced with a red wire. Hard to tell from the pics.

View attachment 533540

The melted wire ran from the welded splice to the instrument regulator.

It appears that originally when I bought the car, the previous owner may have had that wire connected to the point where the radio capacitor is and the two prong spade connector that is supposed to be connected to the ground spade at the radio capacitor was floating. Additionally, the high beam indicator lamp was bad and I have replaced it.

Note: the radio capacitor attaches to the second spade male connector on the instrument regulator.

Now off to find out where the short is…

 

[3175375]

Well, I have repaired the short.
I had thought that there was a short on the high beam indicator, but was mistaken.
I believe that I was measuring resistance through the headlight bulb.

Put it all back together (loosely) and now:

Gas gauge works (reads just over 3/4 tank)
Clock runs
High beam indicator works
Turn signals, emergency flashers, headlights and taillights all work

The only thing that doesn’t work are the instrument panel lamps and I know that it’s the dimmer switch. I have an order into @Devinism , but he’s not able to get to getting me a replacement until next week.

Until then, I am going to button it all up and get some seat time on it.

I also think that the root cause of this 12 v line (from the infamous ‘welded splice’) to the instrument panel regulator maybe was that the regulator shorted, or the previous owner had connected it to the ground stud at the radio capacitor and vice versa.

Thank you all for the comments and especially to @1970FuryConv and @Big_John for the schematic and knowledge sharing!

The best part will be taking my Mom and fiancé out on my Mom’s 85th birthday on Sunday for a cruise. Priceless!!!

 

[1970FuryConv]

Enjoy. You've earned it!