Letting smoke out of the wires.

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cuda65vpt

cuda65vpt

cuda65vpt
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Just had the upholstery done in my 66 Barracuda. My upholsterer hooked the amp gauge wires up to those two posts below the oil pressure gauge instead of the two posts they are supposed to be hooked up to. I put the battery terminal back on and got in to the smell of smoke, thank god I didn't just hook up the battery and walk away.
What is your best guess on what might have fried? I took the dash out and can't see anything obvious. Also in my haste I broke a corner off the dash bezel, so if anybody has a spare...
 
I'll bet a quarter that oil pressure gauge is fryed inside. I wouldn't be surprised if the fuel gauge is fryed also. I doubt the winding in those gauges survived long enough for damage to occur beyond the sender side of the gauge but I would check sender wires from the inst' panel to the senders.

I guess the first thing to do is check the oil pressure gauge. You're looking for 20 ohms post to post. Good luck
 
I'm not intimately familiar with the early clusters, but if it were me, I'd be

pulling the cluster and inspect, repair, etc

pulling the under dash harness at least enough to inspect, IE untaping the red/ black ammeter wires and anything else that might look suspicious and inspect
 
Yep, will be doing all that. I just went out late today to hook up the battery and fire it up, just not LITERALLY!, car has been down for upholstery for over six months.
 
I'm still trying to figure out what other two studs they were connected to.
 
I'll take a pic tomorrow evening. There are two studs on the circuit board right below the oil gauge that accept the same nuts as the two studs they belong on. I think they are grounds for the circuit board.
 
cuda65vpt said:
I'll take a pic tomorrow evening. There are two studs on the circuit board right below the oil gauge that accept the same nuts as the two studs they belong on. I think they are grounds for the circuit board.
Click to expand...

Ouch!
Sounds like it could have been way worse for sure though.
 
cuda65vpt said:
I'll take a pic tomorrow evening. There are two studs on the circuit board right below the oil gauge that accept the same nuts as the two studs they belong on. I think they are grounds for the circuit board.
Click to expand...

I think you are going to learn tjose 2 studs are the Oil gauge mounting/contact posts. They would have the same stud threads but the nuts were supposed to be different from what was used on the ALT' gauge.
After nearly 50 years who knows what nuts you might find.
 
I have a dash bezel for your car, if you still need one.
 
If the uphostery shop was working on the dash pad they would R&R the inst' panel.
 
I thought I should put the dash back in myself while he was doing it, but like the big dummy I am I let him carry on.
I don't see any burnt wires or evidence of fire/melting. All I saw was a wisp of smoke and the brief smell of smoke, I am thinking the Oil Gauge might be the only victim. Where should I connect my OHM meter for the test?
 

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Looks like oil gauge? Was the plug-in harness hooked up, or just the ammeter? I'm sure you burned up the oil gauge, maybe "more."

Put your ohmeter across the two terminals of the gauge and see if they show any continuity. Frankly, I'd just take the dash apart. I'm pretty sure you damaged "some stuff."

Suspects are all the gauges except ammeter, as well as the voltage limiter, which is inside (built into) the fuel gauge I believe.
 
Ohm meter check where you have marked " wires were put here ".
 
Thanks, Is that an auxillary connection point for the oil gauge? The gauge worked before but there was nothing connected to those two posts. I assume it was connected through the 3-pin plug above them.
 
The damage should be limited to the oil gauge or there may be no lasting damage at all. It depends upon which one he connected to which stud. If he connected the red to the ground pin for the gauge you may have cooked some insulation on the back of the board or on some wiring as it would have been a dead short through the cluster chassis. How long was it connected? That would determine if it was long enough to burn through wire insulation. If he connected them the other way so that it grounded through the gauge then I'd say the gauge might be toast. Have to test it to know.
 
Those two posts are for mounting the gauge and connecting it to the circuit board it's mounted to.
 
Good grief ! Neither of those gauge studs is connected directly to chassis ground.
One of them is connected to a pulse voltage from the limiter.
The other is connected to the sender. The studs, muts, printed circuit board, are all parts of these current paths.
When 12 volts from the amp gauge wires went there that current had a path through the oil sender at about 80 ohms. It also had a path to ground through the closed contacts in the mechanical limiter. From there it had a path to ground through all other senders via the printed circuit board and those gauges, nuts, etc..
You're welcome to PM me if you need my help. Good luck
 
KitCarlson said:
There is a partial 66 Barracuda cluster on ebay, $20 starting bid.
Click to expand...
I didn't see that one but found two others on ebay.

Since I am an electrical anti-genius I figured the best way to see what was cooked would be to put the dash back in. The results are that the oil and temp gauges do not work anymore along with all the lights are burned out. Gas gauge still works. How about that? I probably have the only car with a working gas gauge and nothing else, does that make my car a one-of-one?
 
Letting the smoke out of the wires is the easy part, The hard part is putting the smoke back in for the wire to work!!!
 
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